Transmitting/receiving system and method of processing data in the transmitting/receiving system

ABSTRACT

A digital broadcasting system and a data processing method of the same are disclosed. The receiving system includes a receiving unit, a demodulator, a block decoder, and an RS frame decoder. The receiving unit receives a broadcast signal including mobile service data divided into a plurality of output masses, signaling information associated with the mobile service data, and known data. The demodulator demodulates the received broadcast signal. The block decoder block-decodes the demodulated mobile service data of the plurality of output masses based upon the signaling information, thereby outputting the mobile service data of one output mass. And, the RS frame decoder configures an RS frame with the block-decoded and outputted mobile service data, and performs error-correction decoding on the corresponding mobile service data in RS frame units.

This application claims the benefit of U.S. Provisional Application No.61/041,928, filed on Apr. 3, 2008, which is hereby incorporated byreference as if fully set forth herein. And this application claims thebenefit of Korean Application No. 10-2008-0065171, filed on Jul. 4,2008, which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a transmitting system for transmittinga digital broadcasting signal, a receiving system for receiving thedigital broadcasting signal transmitted from the transmitting system,and a method of processing data in the transmitting system and thereceiving system.

2. Discussion of the Related Art

The Vestigial Sideband (VSB) transmission mode, which is adopted as thestandard for digital broadcasting in North America and the Republic ofKorea, is a system using a single carrier method. Therefore, thereceiving performance of the receiving system may be deteriorated in apoor channel environment. Particularly, since resistance to changes inchannels and noise is more highly required when using portable and/ormobile broadcast receivers, the receiving performance may be even moredeteriorated when transmitting mobile service data by the VSBtransmission mode.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to atransmitting/receiving system and a data processing method thatsubstantially obviate one or more problems due to limitations anddisadvantages of the related art.

An object of the present invention is to provide atransmitting/receiving system and a data processing method that arehighly resistant to channel changes and noise.

Another object of the present invention is to provide atransmitting/receiving system and a data processing method that canenhance the receiving performance of the receiving system by performingadditional encoding on mobile service data and by transmitting theprocessed data to the receiving system.

A further object of the present invention is to provide atransmitting/receiving system and a data processing method that can alsoenhance the receiving performance of the receiving system by insertingknown data already known in accordance with a pre-agreement between thereceiving system and the transmitting system in a predetermined regionwithin a data region.

A further object of the present invention is to provide atransmitting/receiving system and a data processing method that can alsoenhance the receiving performance of the receiving system bydiversifying mobile service data into time/frequency section andtransmitting the diversified mobile service data.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, atransmitting system may include a service multiplexer and a transmitter.The service multiplexer may multiplex mobile service data and mainservice data at a predetermined data rate and may transmit themultiplexed data to the transmitter. The transmitter may performadditional encoding on the mobile service data being transmitted fromthe service multiplexer. The transmitter may also group a plurality ofadditionally encoded mobile service data packets so as to form a datagroup. The transmitter may multiplex mobile service data packetsincluding mobile service data and main service data packets includingmain service data and may transmit the multiplexed data packets to areceiving system.

The transmitter may diversify mobile service data into a plurality oftime sections and transmit the diversified mobile service data.

The transmitter may diversify mobile service data into a plurality offrequency sections and transmit the diversified mobile service data.

Herein, the data group may be divided into a plurality of regionsdepending upon a degree of interference of the main service data. Also,a long known data sequence may be periodically inserted in regionswithout interference of the main service data. Also, a receiving systemaccording to an embodiment of the present invention may be used fordemodulating and channel equalizing the known data sequence.

In another aspect of the present invention, a receiving system includesa receiving unit, a demodulator, a block decoder, and a Reed-Solomon(RS) frame decoder. The receiving unit receives a broadcast signalincluding mobile service data divided into a plurality of output masses,signaling information associated with the mobile service data, and knowndata. The demodulator demodulates the received broadcast signal. Theblock decoder block-decodes the demodulated mobile service data of theplurality of output masses based upon the signaling information, therebyoutputting the mobile service data of one output mass. And, theReed-Solomon (RS) frame decoder configures an RS frame with theblock-decoded and outputted mobile service data, and performserror-correction decoding on the corresponding mobile service data in RSframe units.

Herein, the block decoder includes a plurality of input buffers, aplurality of inner decoders, a plurality of symbol deinterleavers, anouter symbol mapper, an outer decoder, an inner symbol mapper, aplurality of symbol interleavers, and an output buffer. The plurality ofinput buffers stores the mobile service data of a corresponding outputmass, and repeatedly output the stored mobile service data in blocksizes for turbo-decoding. The plurality of inner decoders matches dataof a corresponding output mass being turbo-decoded and fed-back withdata being outputted from a respective input buffer in block sizes forturbo-decoding, thereby performing trellis decoding. The plurality ofsymbol deinterleavers block-deinterleaves, in symbol units,soft-decision values of mobile service data of a corresponding outputmass being trellis-decoded and outputted.

Also, the outer symbol mapper configures the plurality of soft-decisionvalues being deinterleaved and outputted from the plurality of symboldeinterleavers into one soft-decision value. The outer decoder receivesthe soft-decision value from the outer symbol mapper and performs symboldecoding. The inner symbol mapper divides the soft-decision value beingsymbol-decoded and outputted from the outer decoder into the pluralityof soft-decision values, and converts the divided soft-decision valuesto fit an input format of the inner decoder corresponding to therespective output mass. The plurality of symbol interleaversblock-interleaves, in symbol units, the soft-decision values of the mainservice data of the corresponding output mass being outputted from theinner symbol mapper, thereby outputting the block-interleaved data tothe inner decoder of the respective output mass. And, the output bufferstores the mobile service data symbol-decoded by the outer decoder,thereby outputting the stored mobile service data.

In another aspect of the present invention, a data processing method ofa digital broadcast receiving system includes the steps of receiving abroadcast signal including mobile service data divided into a pluralityof output masses, signaling information associated with the mobileservice data, and known data, demodulating the received broadcastsignal, block-decoding the demodulated mobile service data of multipleoutput masses based upon the signaling information, thereby outputtingthe mobile service data of one output mass, and configuring aReed-Solomon (RS) frame with the block-decoded and outputted mobileservice data, and performing error-correction decoding on thecorresponding mobile service data in RS frame units.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 illustrates a structure of a MPH frame for transmitting andreceiving mobile service data according to the present invention;

FIG. 2 illustrates an exemplary structure of a VSB frame;

FIG. 3 is a block diagram showing a general structure of a transmittingsystem according to an embodiment of the present invention;

FIG. 4 is a block diagram showing an example of a service multiplexer ofFIG. 3;

FIG. 5 is a block diagram showing an embodiment of a transmitter of FIG.3;

FIG. 6 is a block diagram showing an example of a pre-processor of FIG.5;

FIG. 7 is a block diagram showing another example of a pre-processor ofFIG. 5;

FIG. 8 is a block diagram showing another example of a pre-processor ofFIG. 5;

FIG. 9( a) to FIG. 9( d) illustrate examples of a diversity transmissionaccording to the present invention;

FIG. 10 is a block diagram showing an example of a block processoraccording to present invention;

FIG. 11A and FIG. 11B illustrate examples encoding on mobile servicedata at a coding rate of ¼, and dividing the encoded mobile service datainto two output masses, thereby respectively symbol-interleaving the twooutput masses according to the present invention;

FIG. 12A and FIG. 12B illustrate examples encoding on mobile servicedata at a coding rate of ⅙, and dividing the encoded mobile service datainto two output masses, thereby respectively symbol-interleaving the twooutput masses according to the present invention;

FIG. 13A is a detailed block diagram showing an embodiment of a 1/Nencoder according to the present invention;

FIG. 13B is a detailed block diagram showing another embodiment of a 1/Nencoder according to the present invention;

FIG. 14 is a detailed block diagram showing another embodiment of a 1/Nencoder according to the present invention;

FIG. 15 illustrates a symbol interleaving process according to anembodiment of the present invention;

FIG. 16A illustrates a structure of data group after being datainterleaved according to the present invention;

FIG. 16B illustrates a structure of data group before being datainterleaved according to the present invention;

FIG. 17 illustrates a mapping example of the positions to which thefirst 4 slots of a sub-frame are assigned with respect to a VSB framebased on before being data interleaved according to the presentinvention;

FIG. 18 illustrates an example of data groups of a single ensemble beingassigned (or allocated) to an MPH frame;

FIG. 19 illustrates an example of data groups of a plurality ofensembles being assigned (or allocated) to an MPH frame;

FIG. 20 illustrates an example of data groups of three ensembles beingassigned (or allocated) to an MPH frame;

FIG. 21A to FIG. 21C illustrate examples of transmission parameteraccording to the present invention;

FIG. 22 illustrates an example of power saving when there are threeensembles in a MPH frame according to the present invention;

FIG. 23 illustrates examples of MPH-related information among signalinginformation according to the present invention;

FIG. 24( a) to FIG. 24( e) illustrate an example of signalinginformation scenario being transmitted in signaling information regionaccording to the present invention;

FIG. 25 illustrates a block diagram of a post-processor according to anembodiment of the present invention;

FIG. 26 illustrates a block diagram of a pre-processor according toanother embodiment of the present invention;

FIG. 27 illustrates a block diagram of a demodulating unit of areceiving system according to an embodiment of the present invention;

FIG. 28 illustrates a data structure showing an example of known databeing periodically inserted in actual data according to the presentinvention;

FIG. 29 illustrates a block diagram of a block decoder according toanother embodiment of the present invention;

FIG. 30 illustrates a block diagram of a feedback deformatter accordingto another embodiment of the present invention;

FIG. 31 illustrates a block diagram of a demodulating unit of areceiving system according to another embodiment of the presentinvention;

FIG. 32 illustrates a block diagram of a demodulating unit of areceiving system according to another embodiment of the presentinvention;

FIG. 33 illustrates a block diagram of a demodulating unit of areceiving system according to another embodiment of the presentinvention;

FIG. 34 illustrates a block diagram of a receiving system according toan embodiment of the present invention; and

FIG. 35 illustrates a block diagram of a receiving system according toanother embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts. In addition,although the terms used in the present invention are selected fromgenerally known and used terms, some of the terms mentioned in thedescription of the present invention have been selected by the applicantat his or her discretion, the detailed meanings of which are describedin relevant parts of the description herein. Furthermore, it is requiredthat the present invention is understood, not simply by the actual termsused but by the meaning of each term lying within.

Among the terms used in the description of the present invention, mainservice data correspond to data that can be received by a fixedreceiving system and may include audio/video (A/V) data. Morespecifically, the main service data may include A/V data of highdefinition (HD) or standard definition (SD) levels and may also includediverse data types required for data broadcasting. Also, the known datacorrespond to data pre-known in accordance with a pre-arranged agreementbetween the receiving system and the transmitting system.

Additionally, among the terms used in the present invention, “MPH”corresponds to the initials of “mobile”, “pedestrian”, and “handheld”and represents the opposite concept of a fixed-type system. Furthermore,the MPH service data may include at least one of mobile service data,pedestrian service data, and handheld service data, and will also bereferred to as “mobile service data” for simplicity. Herein, the mobileservice data not only correspond to MPH service data but may alsoinclude any type of service data with mobile or portablecharacteristics. Therefore, the mobile service data according to thepresent invention are not limited only to the MPH service data.

The above-described mobile service data may correspond to data havinginformation, such as program execution files, stock information, and soon, and may also correspond to A/V data. Most particularly, the mobileservice data may correspond to A/V data having lower resolution andlower data rate as compared to the main service data. For example, if anA/V codec that is used for a conventional main service corresponds to aMPEG-2 codec, a MPEG-4 advanced video coding (AVC) or scalable videocoding (SVC) having better image compression efficiency may be used asthe A/V codec for the mobile service. Furthermore, any type of data maybe transmitted as the mobile service data. For example, transportprotocol expert group (TPEG) data for broadcasting real-timetransportation information may be transmitted as the main service data.

Also, a data service using the mobile service data may include weatherforecast services, traffic information services, stock informationservices, viewer participation quiz programs, real-time polls andsurveys, interactive education broadcast programs, gaming services,services providing information on synopsis, character, background music,and filming sites of soap operas or series, services providinginformation on past match scores and player profiles and achievements,and services providing information on product information and programsclassified by service, medium, time, and theme enabling purchase ordersto be processed. Herein, the present invention is not limited only tothe services mentioned above. In the present invention, the transmittingsystem provides backward compatibility in the main service data so as tobe received by the conventional receiving system. Herein, the mainservice data and the mobile service data are multiplexed to the samephysical channel and then transmitted.

In the present invention, the transmitting system provides backwardcompatibility in the main service data so as to be received by theconventional receiving system. Herein, the main service data and themobile service data are multiplexed to the same physical channel andthen transmitted.

Furthermore, the transmitting system according to the present inventionperforms additional encoding on the mobile service data and inserts thedata already known by the receiving system and transmitting system(e.g., known data), thereby transmitting the processed data.

Therefore, when using the transmitting system according to the presentinvention, the receiving system may receive the mobile service dataduring a mobile state and may also receive the mobile service data withstability despite various distortion and noise occurring within thechannel.

MPH Frame Structure

In the embodiment of the present invention, the mobile service data aremodulated in a VSB mode and transmitted to the receiving system. At thispoint, the transmitter groups a plurality of mobile service data packetsto form a RS frame so as to perform an encoding process for errorcorrection. Then, data included in the error correction encoded RS frameare allocated to a plurality of data groups. Subsequently, the pluralityof data groups are multiplexed with the main service data within an MPHframe, thereby transmitted to the receiving system. In the embodiment ofthe present invention, a plurality of data groups to which the dataincluded in the error correction encoded RS frame are allocatedconfigures an ensemble. More specifically, the data groups within anensemble share the same ensemble identification (ID). At this point,since a plurality of mobile services may be included in one RS frame, aplurality of mobile services may also be included in one ensemble. Eachmobile service within an ensemble (or RS frame) may be referred to avirtual channel.

A method of allocating the data groups included in an ensemble within asingle MPH frame will be described in detail in a later process. At thispoint, one MPH frame consists of K1 number of sub-frames, wherein onesub-frame includes K2 number of VSB frames. Each VSB frame consists ofK3 number of slots. In the embodiment of the present invention, K1 willbe set to 5, K2 will be set to 4, and K3 will be set to 4 (i.e., K1=5,K2=4, and K3=4). The values for K1, K2, and K3 presented in thisembodiment either correspond to values according to a preferredembodiment or are merely exemplary. Therefore, the above-mentionedvalues will not limit the scope of the present invention.

FIG. 1 illustrates a structure of a MPH frame for transmitting andreceiving mobile service data according to the present invention. In theexample shown in FIG. 1, one MPH frame consists of 5 sub-frame, whereineach sub-frame includes 4 VSB frames, and wherein each VSB frameincludes 4 slots. In this case, the MPH frame according to the presentinvention includes 5 sub-frames, 20 VSB frames, and 80 slots.

FIG. 2 illustrates an exemplary structure of a VSB frame, wherein oneVSB frame consists of 2 fields (i.e., an odd field and an even field).Herein, each field includes a field synchronization segment and 312 datasegments. More specifically, 2 slots are grouped to form one field, and2 slots are grouped to form one VSB frame. Therefore, one slot includes156 data segments (or packets).

General Description of the Transmitting System

FIG. 3 illustrates a block diagram showing a general structure of atransmitting system according to an embodiment of the present invention.Herein, the transmitting system includes a service multiplexer 100 and atransmitter 200. Herein, the service multiplexer 100 is located in thestudio of each broadcast station, and the transmitter 200 is located ina site placed at a predetermined distance from the studio. Thetransmitter 200 may be located in a plurality of different locations.Also, for example, the plurality of transmitters may share the samefrequency. And, in this case, the plurality of transmitters receives thesame signal. This corresponds to data transmission using SingleFrequency Network (SFN). Accordingly, in the receiving system, a channelequalizer may compensate signal distortion, which is caused by areflected wave, so as to recover the original signal. In anotherexample, the plurality of transmitters may have different frequencieswith respect to the same channel. This corresponds to data transmissionusing Multi Frequency Network (MFN).

A variety of methods may be used for data communication each of thetransmitters, which are located in remote positions, and the servicemultiplexer. For example, an interface standard such as a synchronousserial interface for transport of MPEG-2 data (SMPTE-310M). In theSMPTE-310M interface standard, a constant data rate is decided as anoutput data rate of the service multiplexer. For example, in case of the8 VSB mode, the output data rate is 19.39 Mbps, and, in case of the 16VSB mode, the output data rate is 38.78 Mbps. Furthermore, in theconventional 8 VSB mode transmitting system, a transport stream (TS)packet having a data rate of approximately 19.39 Mbps may be transmittedthrough a single physical channel. Also, in the transmitting systemaccording to the present invention provided with backward compatibilitywith the conventional transmitting system, additional encoding isperformed on the mobile service data. Thereafter, the additionallyencoded mobile service data are multiplexed with the main service datato a TS packet form, which is then transmitted. At this point, the datarate of the multiplexed TS packet is approximately 19.39 Mbps.

At this point, the service multiplexer 100 receives at least one type ofmobile service data and program specific information/program and systeminformation protocol (PSI/PSIP) table data for each mobile service so asto encapsulate the received data to each TS packet. Also, the servicemultiplexer 100 receives at least one type of main service data andPSI/PSIP table data for each main service and encapsulates the receiveddata to a transport stream (TS) packet. Subsequently, the TS packets aremultiplexed according to a predetermined multiplexing rule and outputsthe multiplexed packets to the transmitter 200.

Service Multiplexer

FIG. 4 illustrates a block diagram showing an example of the servicemultiplexer. The service multiplexer includes a controller 110 forcontrolling the overall operations of the service multiplexer, aPSI/PSIP generator 120 for the main service, a table informationgenerator 130 for the mobile service, a null packet generator 140, amobile service multiplexer 150, and a transport multiplexer 160.According to the embodiment of the present invention, the tableinformation generator 130 generates table data, which is configured inthe form of an MPEG-2 private section. For example, the tableinformation generator 130 generates PSI/PSIP table data.

The transport multiplexer 160 may include a main service multiplexer 161and a transport stream (TS) packet multiplexer 162.

Referring to FIG. 4, at least one type of compression encoded mainservice data and the PSI/PSIP table data generated from the PSI/PSIPgenerator 120 for the main service are inputted to the main servicemultiplexer 161 of the transport multiplexer 160. The main servicemultiplexer 161 encapsulates each of the inputted main service data andPSI/PSIP table data to MPEG-2 TS packet forms. Then, the MPEG-2 TSpackets are multiplexed and outputted to the TS packet multiplexer 162.Herein, the data packet being outputted from the main servicemultiplexer 161 will be referred to as a main service data packet forsimplicity.

Thereafter, at least one type of the compression encoded mobile servicedata and the PSI/PSIP table data generated from the table informationgenerator 130 for the mobile service are inputted to the mobile servicemultiplexer 150. The mobile service multiplexer 150 encapsulates each ofthe inputted mobile service data and PSI/PSIP table data to MPEG-2 TSpacket forms. Then, the MPEG-2 TS packets are multiplexed and outputtedto the TS packet multiplexer 162. Herein, the data packet beingoutputted from the mobile service multiplexer 150 will be referred to asa mobile service data packet for simplicity. At this point, thetransmitter 200 requires identification information in order to identifyand process the main service data packet and the mobile service datapacket. Herein, the identification information may use valuespre-decided in accordance with an agreement between the transmittingsystem and the receiving system, or may be configured of a separate setof data, or may modify predetermined location value with in thecorresponding data packet. As an example of the present invention, adifferent packet identifier (PID) may be assigned to identify each ofthe main service data packet and the mobile service data packet.

In another example, by modifying a synchronization data byte within aheader of the mobile service data, the service data packet may beidentified by using the synchronization data byte value of thecorresponding service data packet. For example, the synchronization byteof the main service data packet directly outputs the value decided bythe ISO/IEC13818-1 standard (i.e., 0×47) without any modification. Thesynchronization byte of the mobile service data packet modifies andoutputs the value, thereby identifying the main service data packet andthe mobile service data packet. Conversely, the synchronization byte ofthe main service data packet is modified and outputted, whereas thesynchronization byte of the mobile service data packet is directlyoutputted without being modified, thereby enabling the main service datapacket and the mobile service data packet to be identified.

A plurality of methods may be applied in the method of modifying thesynchronization byte. For example, each bit of the synchronization bytemay be inversed, or only a portion of the synchronization byte may beinversed. As described above, any type of identification information maybe used to identify the main service data packet and the mobile servicedata packet. Therefore, the scope of the present invention is notlimited only to the example set forth in the description of the presentinvention.

Meanwhile, a transport multiplexer used in the conventional digitalbroadcasting system may be used as the transport multiplexer 160according to the present invention. More specifically, in order tomultiplex the mobile service data and the main service data and totransmit the multiplexed data, the data rate of the main service islimited to a data rate of (19.39-K) Mbps. Then, K Mbps, whichcorresponds to the remaining data rate, is assigned as the data rate ofthe mobile service. Thus, the transport multiplexer which is alreadybeing used may be used as it is without any modification. Herein, thetransport multiplexer 160 multiplexes the main service data packet beingoutputted from the main service multiplexer 161 and the mobile servicedata packet being outputted from the mobile service multiplexer 150.Thereafter, the transport multiplexer 160 transmits the multiplexed datapackets to the transmitter 200.

However, in some cases, the output data rate of the mobile servicemultiplexer 150 may not be equal to K Mbps. In this case, the mobileservice multiplexer 150 multiplexes and outputs null data packetsgenerated from the null packet generator 140 so that the output datarate can reach K Mbps. More specifically, in order to match the outputdata rate of the mobile service multiplexer 150 to a constant data rate,the null packet generator 140 generates null data packets, which arethen outputted to the mobile service multiplexer 150. For example, whenthe service multiplexer 100 assigns K Mbps of the 19.39 Mbps to themobile service data, and when the remaining (19.39-K) Mbps is,therefore, assigned to the main service data, the data rate of themobile service data that are multiplexed by the service multiplexer 100actually becomes lower than K Mbps. This is because, in case of themobile service data, the pre-processor of the transmitting systemperforms additional encoding, thereby increasing the amount of data.Eventually, the data rate of the mobile service data, which may betransmitted from the service multiplexer 100, becomes smaller than KMbps.

For example, since the pre-processor of the transmitter performs anencoding process on the mobile service data at a coding rate of at least½, the amount of the data outputted from the pre-processor is increasedto more than twice the amount of the data initially inputted to thepre-processor. Therefore, the sum of the data rate of the main servicedata and the data rate of the mobile service data, both beingmultiplexed by the service multiplexer 100, becomes either equal to orsmaller than 19.39 Mbps. Therefore, in order to match the data rate ofthe data that are finally outputted from the service multiplexer 100 toa constant data rate (e.g., 19.39 Mbps), an amount of null data packetscorresponding to the amount of lacking data rate is generated from thenull packet generator 140 and outputted to the mobile servicemultiplexer 150.

Accordingly, the mobile service multiplexer 150 encapsulates each of themobile service data and the PSI/PSIP table data that are being inputtedto a MPEG-2 TS packet form. Then, the above-described TS packets aremultiplexed with the null data packets and, then, outputted to the TSpacket multiplexer 162. Thereafter, the TS packet multiplexer 162multiplexes the main service data packet being outputted from the mainservice multiplexer 161 and the mobile service data packet beingoutputted from the mobile service multiplexer 150 and transmits themultiplexed data packets to the transmitter 200 at a data rate of 19.39Mbps.

According to an embodiment of the present invention, the mobile servicemultiplexer 150 receives the null data packets. However, this is merelyexemplary and does not limit the scope of the present invention. Inother words, according to another embodiment of the present invention,the TS packet multiplexer 162 may receive the null data packets, so asto match the data rate of the finally outputted data to a constant datarate. Herein, the output path and multiplexing rule of the null datapacket is controlled by the controller 110. The controller 110 controlsthe multiplexing processed performed by the mobile service multiplexer150, the main service multiplexer 161 of the transport multiplexer 160,and the TS packet multiplexer 162, and also controls the null datapacket generation of the null packet generator 140. At this point, thetransmitter 200 discards the null data packets transmitted from theservice multiplexer 100 instead of transmitting the null data packets.

Further, in order to allow the transmitter 200 to discard the null datapackets transmitted from the service multiplexer 100 instead oftransmitting them, identification information for identifying the nulldata packet is required. Herein, the identification information may usevalues pre-decided in accordance with an agreement between thetransmitting system and the receiving system. For example, the value ofthe synchronization byte within the header of the null data packet maybe modified so as to be used as the identification information.Alternatively, a transport_error_indicator flag may also be used as theidentification information.

In the description of the present invention, an example of using thetransport_error_indicator flag as the identification information will begiven to describe an embodiment of the present invention. In this case,the transport_error_indicator flag of the null data packet is set to‘1’, and the transport_error_indicator flag of the remaining datapackets are reset to ‘0’, so as to identify the null data packet. Morespecifically, when the null packet generator 140 generates the null datapackets, if the transport_error_indicator flag from the header field ofthe null data packet is set to ‘1’ and then transmitted, the null datapacket may be identified and, therefore, be discarded. In the presentinvention, any type of identification information for identifying thenull data packets may be used. Therefore, the scope of the presentinvention is not limited only to the examples set forth in thedescription of the present invention.

According to another embodiment of the present invention, a transmissionparameter may be included in at least a portion of the null data packet,or at least one table or an operations and maintenance (OM) packet (orOMP) of the PSI/PSIP table for the mobile service. In this case, thetransmitter 200 extracts the transmission parameter and outputs theextracted transmission parameter to the corresponding block and alsotransmits the extracted parameter to the receiving system if required.More specifically, a packet referred to as an OMP is defined for thepurpose of operating and managing the transmitting system. For example,the OMP is configured in accordance with the MPEG-2 TS packet format,and the corresponding PID is given the value of 0×1FFA. The OMP isconfigured of a 4-byte header and a 184-byte payload. Herein, among the184 bytes, the first byte corresponds to an OM_type field, whichindicates the type of the OM packet.

In the present invention, the transmission parameter may be transmittedin the form of an OMP. And, in this case, among the values of thereserved fields within the OM_type field, a pre-arranged value is used,thereby indicating that the transmission parameter is being transmittedto the transmitter 200 in the form of an OMP. More specifically, thetransmitter 200 may find (or identify) the OMP by referring to the PID.Also, by parsing the OM_type field within the OMP, the transmitter 200can verify whether a transmission parameter is included after theOM_type field of the corresponding packet. The transmission parametercorresponds to supplemental data required for processing mobile servicedata from the transmitting system and the receiving system.

Herein, the transmission parameter may include data group information,region information within the data group, RS frame information, superframe information, MPH frame information, ensemble information, and RScode information. The transmission parameter may also includeinformation on how signals of a symbol domain are encoded in order totransmit the mobile service data, and multiplexing information on howthe main service data and the mobile service data or various types ofmobile service data are multiplexed. The information included in thetransmission parameter is merely exemplary to facilitate theunderstanding of the present invention.

And, the adding and deleting of the information included in thetransmission parameter may be easily modified and changed by anyoneskilled in the art. Therefore, the present invention is not limited tothe examples proposed in the description set forth herein.

Furthermore, the transmission parameters may be provided from theservice multiplexer 100 to the transmitter 200. Alternatively, thetransmission parameters may also be set up by an internal controller(not shown) within the transmitter 200 or received from an externalsource.

Transmitter

FIG. 5 illustrates a block diagram showing an example of the transmitter200 according to an embodiment of the present invention. Herein, thetransmitter 200 includes a demultiplexer 210, a packet jitter mitigator220, a pre-processor 230, a packet multiplexer 240, a post-processor250, a synchronization (sync) multiplexer 260, and a transmission unit270. Herein, when a data packet is received from the service multiplexer100, the demultiplexer 210 should identify whether the received datapacket corresponds to a main service data packet, a mobile service datapacket, or a null data packet. For example, the demultiplexer 210 usesthe PID within the received data packet so as to identify the mainservice data packet and the mobile service data packet. Then, thedemultiplexer 210 uses a transport_error_indicator field to identify thenull data packet. The main service data packet identified by thedemultiplexer 210 is outputted to the packet jitter mitigator 220, themobile service data packet is outputted to the pre-processor 230, andthe null data packet is discarded. If a transmission parameter isincluded in the null data packet, then the transmission parameter isfirst extracted and outputted to the corresponding block. Thereafter,the null data packet is discarded.

The pre-processor 230 performs an additional encoding process of themobile service data included in the service data packet, which isdemultiplexed and outputted from the demultiplexer 210. Thepre-processor 230 also performs a process of configuring a data group sothat the data group may be positioned at a specific place in accordancewith the purpose of the data, which are to be transmitted on atransmission frame. This is to enable the mobile service data to respondswiftly and strongly against noise and channel changes. Thepre-processor 230 may also refer to the transmission parameter whenperforming the additional encoding process. Also, the pre-processor 230groups a plurality of mobile service data packets to configure a datagroup. Thereafter, known data, mobile service data, RS parity data, andMPEG header are allocated to pre-determined regions within the datagroup.

Also, by diversifying (or dispersing) the input data by time and/orfrequency, the pre-processor 230 is made to be more robust against theburst noise than that of the related art. Hereinafter, the process ofscattering and transmitting the input data by time and/or frequency willbe referred to as diversity transmission for simplicity. Additionally,the number of times the data of the same information are divided andtransmitted over different time sections or frequency sections will bereferred to as a diversity degree.

The process of scattering the input data by time, the process ofscattering the input data by frequency, and the process of scatteringthe input data by time and frequency will hereinafter be separatelydescribed.

The input data may correspond to mobile service data, or correspond toknown data, or correspond to signaling information, such as atransmission parameter. The process of scattering and transmitting themobile service data by time and/or frequency will be described as anembodiment of the present invention.

The Pre-Processor of a First Embodiment

The pre-processor according to the first embodiment to the presentinvention is for scattering the mobile service data on the time sectionas many times as the diversity degree, thereby outputting the scattereddata.

FIG. 6 illustrates a block diagram showing the structure of thepre-processor 230 according to the first embodiment of the presentinvention. Herein, the pre-processor 230 includes a data randomizer 301,an RS frame encoder 302, a block processor 303, a diversity buffer 304,a diversity controller 305, a group formatter 306, a data deinterleaver307, a packet formatter 308, and a signaling encoder 309.

The data randomizer 301 within the above-described pre-processor 230randomizes the mobile service data packet including the mobile servicedata that is inputted through the demultiplexer 210. Then, the datarandomizer 301 outputs the randomized mobile service data packet to theRS frame encoder 302. At this point, since the data randomizer 301performs the randomizing process on the mobile service data, therandomizing process that is to be performed by the data randomizer 601of the post-processor 250 on the mobile service data may be omitted. Thedata randomizer 301 may also discard the synchronization byte within themobile service data packet and perform the randomizing process. This isan option that may be chosen by the system designer. In the examplegiven in the present invention, the randomizing process is performedwithout discarding the synchronization byte within the mobile servicedata packet.

The RS frame encoder 302 groups a plurality of mobile service datapackets that is randomized and inputted, so as to create a RS frame.Then, the RS frame encoder 302 performs at least one of an errorcorrection encoding process and an error detection encoding process inRS frame units. Accordingly, robustness may be provided to the mobileservice data, thereby scattering group error that may occur duringchanges in a frequency environment, thereby enabling the mobile servicedata to respond to the frequency environment, which is extremelyvulnerable and liable to frequent changes.

Also, the RS frame encoder 302 groups a plurality of RS frames so as tocreate a super frame, thereby performing a row permutation process insuper frame units. The row permutation process may also be referred toas a row interleaving process. Hereinafter, the process will be referredto as row permutation for simplicity.

More specifically, when the RS frame encoder 302 performs the process ofpermuting each row of the super frame in accordance with apre-determined rule, the position of the rows within the super framebefore and after the row permutation process is changed. If the rowpermutation process is performed by super frame units, and even thoughthe section having a plurality of errors occurring therein becomes verylong, and even though the number of errors included in the RS frame,which is to be decoded, exceeds the extent of being able to becorrected, the errors become dispersed within the entire super frame.Thus, the decoding ability is even more enhanced as compared to a singleRS frame.

At this point, as an example of the present invention, RS-encoding isapplied for the error correction encoding process, and a cyclicredundancy check (CRC) encoding is applied for the error detectionprocess in the RS frame encoder 302. When performing the RS-encoding,parity data that are used for the error correction are generated. And,when performing the CRC encoding, CRC data that are used for the errordetection are generated.

The RS encoding is one of forward error correction (FEC) methods. TheFEC corresponds to a technique for compensating errors that occur duringthe transmission process. The CRC data generated by CRC encoding may beused for indicating whether or not the mobile service data have beendamaged by the errors while being transmitted through the channel. Inthe present invention, a variety of error detection coding methods otherthan the CRC encoding method may be used, or the error correction codingmethod may be used to enhance the overall error correction ability ofthe receiving system.

Herein, the RS frame encoder 302 refers to a pre-determined transmissionparameter and/or the transmission parameter provided from the servicemultiplexer 100 so as to perform operations including RS frameconfiguration, RS encoding, CRC encoding, super frame configuration, androw permutation in super frame units.

The mobile service data, which encoding process in RS frame units androw permutation process in super frame units performed, is output to theblock processor 303.

The block processor 303 encodes the inputted mobile service data onceagain at a coding rate of 1/N (wherein N is an integer equal to orgreater than 2, N≧2).

At this point, the diversity controller 305 controls the block processor303 and the diversity buffer 304 in accordance with the designateddiversity degree and transmission method (for example, any one diversitymethod by time, by frequency, and by time and frequency), therebyenabling the RS-frame-encoded mobile service data symbol to betransmitted to different symbol sections by time and/or frequency.

If the transmission method corresponds to a diversity method by time,the block processor 303 encodes the inputted mobile service data at acoding rate of 1/N. The block processor 303 then scatters the 1/N-rateencoded mobile service data within the time section as many times as thediversity degree, thereby outputting the scattered mobile service datato the diversity buffer 304. For example, when the coding rate is ¼, andwhen the diversity degree is ‘2’, the mobile service data encoded at acoding rate of ¼ is divided and transmitted to two time sections.Herein, the ¼-rate encoded data refers to 1 bit of input data beingencoded and outputted as 4 bits. In this case, 4 bits are not alloutputted to the k^(th) time order. Instead, 2 bits of the 4 bits areoutputted to the k^(th) time order, and the remaining 2 bits areoutputted to the (k+1)^(th) time order. In another example, when thecoding rate is ⅙, and when the diversity degree is ‘3’, the mobileservice data encoded at a coding rate of ⅙ is divided and transmitted tothree time sections. Herein, the ⅙-rate encoded data refers to 1 bit ofinput data being encoded and outputted as 6 bits. In this case, 6 bitsare not all outputted to the k^(th) time order. Instead, 2 bits of the 6bits are outputted to the k^(th) time order, the next 2 bits areoutputted to the (k+1)^(th) time order, and the remaining 2 bits areoutputted to the (k+2)^(th) time order. In yet another example, the samedata may be scattered and outputted to multiple time sections. Forexample, 2 bits of ½-rate coded mobile service data may be repeatedlyoutputted to the k^(th) time order and the (k+1)^(th) time order.

The diversity buffer 304 temporarily stores the mobile service datascattered in the time section. Then, the diversity buffer 304 outputsthe corresponding mobile service data in the decided order to the groupformatter 306.

At this point, any one unit that can collectively process data, such asMPH block, MPH group, MPH frame, and so on, may be applied as thescattering (or dispersion) and transmission unit. In the presentinvention, the MPH frame will be described as the processing unitaccording to the first embodiment of the present invention.

More specifically, when data of one MPH frame section are encoded at thecoding rate of ¼, and when the ¼-rate coded data are then scattered totwo different time sections, the ¼-rate encoded data are scattered andstransmitted to two MPH frames.

Thereafter, when the block processor 303 encodes the data of twochronologically consecutive MPH frame sections at the coding rate of ¼and then scatters the ¼-rate encoded data to 4 different time sections,the scattered data rate transmitted from the diversity buffer 304 asshown in FIG. 9( a). First of all, in the k^(th) time order, the blockprocessor 303 encodes the mobile service data of one MPH frame sectionat a coding rate of ¼. Then, the block processor 303 divides the ¼-rateencoded mobile service data into two output masses (or groups) (i.e.,mob Ak, mob Bk), thereby outputting the processed mobile service data tothe diversity buffer 304. For example, among the ¼-rate encoded mobileservice data in one MPH frame section, one output mass outputs ½-rateencoded mobile service data (Ak), and another output mass outputs theremaining ½-rate encoded mobile service data (Bk). Additionally, in the(k+1)^(th) time order, the block processor 303 encodes the mobileservice data of a next MPH frame section at a coding rate of ¼. Then,the block processor 303 divides the ¼-rate encoded mobile service datainto two output masses (i.e., mob Ak+1, mob Bk+1), thereby outputtingthe processed mobile service data to the diversity buffer 304.

The diversity buffer 304 temporarily stores the mobile service data (mobAk, mob Bk, mob Ak+1, mob Bk+1) that are scattered and inputted. Then,the diversity buffer 304 outputs the temporarily stored mobile servicedata to the group formatter 306 by a pre-decided order. For example, asshown in FIG. 9( a), the mobile service data of each output mass arerespectively carried over 4 MPH frame by the order of mob Ak, mob Bk,mob Ak+1, and mob Bk+1, thereby being outputted to the group formatter306. More specifically, the diversity buffer 304 breaks down (ordivides) mob Ak to group units, so that mob Ak can be first processed bythe group formatter 306. Then, when the output of mob Ak is completed,mob Ak+1 is outputted. Thereafter, the remaining data are outputtedusing the same method by the order shown in FIG. 9( a).

The above-described output order of multiple output masses in thediversity buffer 304 is merely exemplary in order to facilitate theunderstanding of the present invention. According to another embodimentof the present invention, the diversity buffer 304 may also load themobile service data of each output mass in 4 different MPH frames by theorder of mob Ak, mob Bk, mob Ak+1, mob Bk+1, thereby outputting thecorresponding mobile service data. As described above, the output orderof multiple output masses in the diversity buffer 304 may be modified bythe system designer. Therefore, the present invention will not belimited only to the example set forth herein.

Any data section that can group (or collect) and process data, such asan MPH group, an MPH frame, etc., may be used as the transmission unit dand the transmission cycle period t shown in FIG. 9( a) to FIG. 9( d).

In addition, various processing information for diversity transmission(hereinafter referred to as diversity processing information) aremodified by the diversity controller 305. And, such diversity processinginformation is processed by the group formatter 306 as signalinginformation, thereby being outputted along with the mobile service data.For example, the diversity processing information may correspond to adiversity degree, a transmission unit d, a transmission cycle period t,and output order of output masses from the diversity buffer 304.

Meanwhile, the group formatter 306 inserts the mobile service data beingoutputted from the diversity buffer 304 in a corresponding region withina data group, which is formed based upon a pre-decided rule. Also, withrespect to data deinterleaving, the group formatter 306 inserts variousplace holders or known data (or known data place holders) in thecorresponding region within the data group. Furthermore, the groupformatter 306 also inserts the diversity processing information, whichis outputted from the diversity controller 305, as signaling informationin a corresponding region within the data group.

At this point, one data group may be divided into one or morehierarchical regions. Herein, the type of mobile service data beinginserted in each region may vary depending upon the characteristic ofeach hierarchical region. Also, each region may be categorized based onthe receiving performance within the data group. In the example of thepresent invention, one data group is divided into regions A, B, C, and Din the data structure prior to data deinterleaving.

FIG. 16A illustrates an alignment of divided data after datainterleaving, and FIG. 16B illustrates an alignment of divided dataprior to data interleaving. More specifically, the data structure shownin FIG. 16A is transmitted to the receiving system. In other words, onetransport packet is interleaved by a data interleaver and, then,scattered to a plurality of data segments, thereby being transmitted tothe receiving system. FIG. 16A shows an example of one data group beingscattered to 170 data segments. At this point, since one 207-byte packethas the same data size as one data segment, the data packet prior tobeing data-interleaved may be considered and used as a data segment.

Furthermore, a data group formed to have a structure, as shown in FIG.16A, is inputted to the data deinterleaver 307.

FIG. 16A shows an example of dividing a data group prior to beingdata-interleaved into 10 MPH blocks (i.e., MPH block 1 (B1) to MPH block10 (B10)). In this example, each MPH block has the length of 16segments. Referring to FIG. 16A, only the RS parity data are allocatedto portions of the first 5 segments of the MPH block 1 (B1) and the last5 segments of the MPH block 10 (B10). The RS parity data are excluded inregions A to D of the data group. When it is assumed that one data groupis divided into regions A, B, C, and D, each MPH block may be includedin any one of region A to region D depending upon the characteristic ofeach MPH block within the data group.

Herein, the data group is divided into a plurality of regions to be usedfor different purposes. More specifically, a region of the main servicedata having no interference or a very low interference level may beconsidered to have a more resistant (or stronger) receiving performanceas compared to regions having higher interference levels. Additionally,when using a system inserting and transmitting known data in the datagroup, and when consecutively long known data are to be periodicallyinserted in the mobile service data, the known data having apredetermined length may be periodically inserted in the region havingno interference from the main service data (i.e., a region wherein themain service data are not mixed). However, due to interference from themain service data, it is difficult to periodically insert known data andalso to insert consecutively long known data to a region havinginterference from the main service data.

Referring to FIG. 16A, MPH block 4 (B4) to MPH block 7 (B7) correspondto regions without interference of the main service data. MPH block 4(B4) to MPH block 7 (B7) within the data group shown in FIG. 16Acorrespond to a region where no interference from the main service dataoccurs. In this example, a long known data sequence is inserted at boththe beginning and end of each MPH block. In the description of thepresent invention, the region including MPH block 4 (B4) to MPH block 7(B7) will be referred to as “region A”. As described above, when thedata group includes region A having a long known data sequence insertedat both the beginning and end of each MPH block, the receiving system iscapable of performing equalization by using the channel information thatcan be obtained from the known data. Therefore, the strongest equalizingperformance may be yielded (or obtained) from one of region A to regionD.

In the example of the data group shown in FIG. 16A, MPH block 3 (B3) andMPH block 8 (B8) correspond to a region having little interference fromthe main service data. Herein, a long known data sequence is inserted inonly one side of each MPH block B3 and B8. More specifically, due to theinterference from the main service data, a long known data sequence isinserted at the end of MPH block 3 (B3), and another long known datasequence is inserted at the beginning of MPH block 8 (B8). In thepresent invention, the region including MPH block 3 (B3) and MPH block 8(B8) will be referred to as “region B”. As described above, when thedata group includes region B having a long known data sequence insertedat only one side (beginning or end) of each MPH block, the receivingsystem is capable of performing equalization by using the channelinformation that can be obtained from the known data. Therefore, astronger equalizing performance as compared to region C/D may be yielded(or obtained).

Referring to FIG. 16A, MPH block 2 (B2) and MPH block 9 (B9) correspondto a region having more interference from the main service data ascompared to region B. A long known data sequence cannot be inserted inany side of MPH block 2 (B2) and MPH block 9 (B9). Herein, the regionincluding MPH block 2 (B2) and MPH block 9 (B9) will be referred to as“region C”. Finally, in the example shown in FIG. 16A, MPH block 1 (B1)and MPH block 10 (B10) correspond to a region having more interferencefrom the main service data as compared to region C. Similarly, a longknown data sequence cannot be inserted in any side of MPH block 1 (B1)and MPH block 10 (B10). Herein, the region including MPH block 1 (B1)and MPH block 10 (B10) will be referred to as “region D”. Since regionC/D is spaced further apart from the known data sequence, when thechannel environment undergoes frequent and abrupt changes, the receivingperformance of region C/D may be deteriorated.

FIG. 16B illustrates a data structure prior to data interleaving. Morespecifically, FIG. 16B illustrates an example of 118 data packets beingallocated to a data group. FIG. 16B shows an example of a data groupconsisting of 118 data packets, wherein, based upon a reference packet(e.g., a 1^(st) packet (or data segment) or 157^(th) packet (or datasegment) after a field synchronization signal), when allocating datapackets to a VSB frame, 37 packets are included before the referencepacket and 81 packets (including the reference packet) are includedafterwards.

The size of the data groups, number of hierarchical regions within thedata group, the size of each region, the number of MPH blocks includedin each region, the size of each MPH block, and so on described aboveare merely exemplary. Therefore, the present invention will not belimited to the examples described above.

Also, apart from the encoded mobile service data outputted from thediversity buffer 304, the group formatter 306 also inserts MPEG headerplace holders, non-systematic RS parity place holders, main service dataplace holders, which are associated with the data deinterleaving in alater process, as shown in FIG. 16A. Herein, the main service data placeholders are inserted because the mobile service data bytes and the mainservice data bytes are alternately mixed with one another in regions Bto D based upon the input of the data deinterleaver, as shown in FIG.16A. For example, based upon the data outputted after datadeinterleaving, the place holder for the MPEG header may be allocated atthe very beginning of each packet.

Furthermore, the group formatter 306 either inserts known data generatedin accordance with a pre-determined method or inserts known data placeholders for inserting the known data in a later process. Additionally,place holders for initializing the trellis encoding module 606 are alsoinserted in the corresponding regions. For example, the initializationdata place holders may be inserted in the beginning of the known datasequence.

The output of the group formatter 306 is inputted to the datadeinterleaver 307. And, the data deinterleaver 307 deinterleaves data byperforming an inverse process of the data interleaver on the data andplace holders within the data group, which are then outputted to thepacket formatter 308. More specifically, when the data and place holderswithin the data group configured, as shown in FIG. 16A, aredeinterleaved by the data deinterleaver 307, the data group beingoutputted to the packet formatter 308 is configured to have thestructure shown in FIG. 16B.

The packet formatter 308 removes the main service data place holders andthe RS parity place holders that were allocated for the deinterleavingprocess from the deinterleaved data being inputted. Then, the packetformatter 308 groups the remaining portion and replaces the 4-byte MPEGheader place holder with an MPEG header having a null packet PID (or anunused PID from the main service data packet). Also, when the groupformatter 306 inserts known data place holders, the packet formatter 308may insert actual known data in the known data place holders, or maydirectly output the known data place holders without any modification inorder to make replacement insertion in a later process. Thereafter, thepacket formatter 308 identifies the data within the packet-formatteddata group, as described above, as a 188-byte unit mobile service datapacket (i.e., MPEG TS packet), which is then provided to the packetmultiplexer 240.

The Pre-Processor of a Second Embodiment

The pre-processor according to the second embodiment to the presentinvention is for scattering the mobile service data on the frequencysection as many times as the diversity degree, thereby outputting theprocessed data. More specifically, in the second embodiment of thepresent invention, the mobile service data are encoded at a coding rateof 1/N at each time order. Subsequently, the 1/N-rate encoded mobileservice data are scattered to a plurality of frequency channelscorresponding to the diversity degree, so as to be transmitted in thesame transmission unit and cycle period.

FIG. 7 illustrates a block diagram showing the structure of thepre-processor 230 according to a second embodiment of the presentinvention, wherein the diversity degree is ‘2’. Referring to FIG. 7, thepre-processor according to the second embodiment of the presentinvention includes a data randomizer 311, an RS frame encoder 312, ablock processor 313, first and second group formatters 314 and 314-1,first and second data deinterleaver 315 and 315-1, first and secondpacket formatter 316 and 316-1, a signaling encoder 317, and a diversitycontroller 310.

Herein, the operations of the data randomizer 311 and the RS frameencoder 312 included in the pre-processor having the above-describedstructure are identical to those of the data randomizer 301 and the RSframe encoder 302 shown in FIG. 6. Therefore, a detailed description ofthe same will be omitted for simplicity.

More specifically, the mobile service data being processed with RS-frameunit encoding and super-frame unit row permutation from the RS frameencoder 312 are outputted to the block processor 313.

The block processor 313 then encodes the inputted mobile service dataonce again at a coding rate of 1/N (wherein N is an integer equal to orgreater than 2, N≧2). At this point, the diversity controller 310controls the block processor 313 in accordance with the designateddiversity degree and transmission method (for example, any one diversitymethod by time, by frequency, and by time and frequency), therebyenabling the RS-frame-encoded mobile service data symbol to betransmitted to different symbol sections by time and/or frequency.

If the transmission method corresponds to a diversity method byfrequency, a number of processing blocks corresponding to the diversitydegree value should be provided in parallel after the block processor313. For example, a number of group formatter, data deinterleaver,packet formatter, packet multiplexer, and post-processor correspondingto the diversity degree value are provided in parallel.

FIG. 7 illustrates a block diagram showing a detailed structure of thepre-processor, when it is assumed that the diversity degree is ‘2’.Herein, two group formatters 313 and 313-1, two data deinterleavers 314and 314-1, and two packet formatters 315 and 315-1 are each provided inparallel.

More specifically, based upon the control of the diversity controller310, the block processor 313 encodes the inputted mobile service data ata coding rate of 1/N, the 1/N-rate encoded mobile service data aredivided into 2 output masses and outputted to the first and second groupformatters 314 and 314-1, respectively. The operations of the first andsecond group formatters 314 and 314-1 are identical to the operation ofthe group formatter 306 shown in FIG. 6. Therefore, a detaileddescription of the same will be omitted for simplicity.

The output of the first group formatter 314 is inputted to the firstdata deinterleaver 315 and deinterleaved, thereby being outputted to thefirst packet formatter 316. The output of the second group formatter314-1 is inputted to the second data deinterleaver 315-1 anddeinterleaved, thereby being outputted to the second packet formatter316-1. Similarly, the operations of the first and second datadeinterleavers 315 and 315-1 and the first and second packet formatters316 and 316-1 are identical to the operations of the data deinterleaver307 and packet formatter 308 shown in FIG. 6. Therefore, a detaileddescription of the same will be omitted for simplicity. The mobileservice data of each MPH frame section being outputted from the firstand second packet formatters 316 and 316-1 transmitted to differentfrequency channels through each of the packet multiplexer and thepost-processor, which are provided in parallel in correspondence withthe diversity degree value.

For example, when the coding rate is ¼, and when the diversity degree is‘2’, the ¼-rate encoded mobile service data are scattered to twofrequency sections and then transmitted. More specifically, instead ofoutputting all 4 bits of the mobile service data, which are encoded at acoding rate of ¼ to the same frequency, among the 4 bits, 2 bits areoutputted to frequency F1 (#1), and the remaining 2 bits are outputtedto frequency F2 (#2) (wherein, frequency F1≠ frequency F2). In anotherexample, when the coding rate is ⅙, and when the diversity degree is‘3’, among the 6 bits, 2 bits are outputted to frequency F1 (#1), thenext 2 bits are outputted to frequency F2 (#2), and the remaining 2 bitsare outputted to frequency F3 (#3) (wherein, F1≠F2≠F3). In yet anotherexample, the same data may be scattered and outputted to multiplefrequency sections. For example, 2 bits of ½-rate coded mobile servicedata may be identically outputted to frequency F1 and frequency F2.

According to the embodiment of the present invention, the mobile servicedata that are to be transmitted to frequency F1 (#1) are outputted tothe first group formatter 314, and the mobile service data that are tobe transmitted to frequency F2 (#2) are outputted to the second groupformatter 314-1.

At this point, any one unit that can collectively process data, such asMPH block, MPH group, MPH frame, and so on, may be applied as thescattering (or dispersion) and transmission unit. In the presentinvention, the MPH frame will be described as the processing unitaccording to the first embodiment of the present invention.

More specifically, when data of one MPH frame section are encoded at thecoding rate of ¼, and when the ¼-rate coded data are then scattered totwo different frequency sections, the ¼-rate encoded data are scatteredand transmitted to two MPH frames over two different frequency channels.When the mobile service data of the MPH frame section are encoded at thecoding rate of ¼ and scattered to two frequency sections, the scatteredmobile service data are transmitted using the method shown in FIG. 9(b).

First of all, in the k^(th) time order, the block processor 313 encodesthe mobile service data of one MPH frame section at a coding rate of ¼.Then, the block processor 313 divides the ¼-rate encoded mobile servicedata into two output masses (or groups) (i.e., mob Ak, mob Bk). Also, inorder to be carried and transmitted over frequency F1 (#1), the mobileservice data of the output mass mob Ak are outputted to the first groupformatter 314. And, in order to be carried and transmitted overfrequency F2 (#2), the mobile service data of the output mass mob Bk areoutputted to the second group formatter 314-1.

Subsequently, in the (k+1)^(th) time order, the block processor 313encodes the mobile service data of a next MPH frame section at a codingrate of ¼. Then, the block processor 313 divides the ¼-rate encodedmobile service data into two output masses (i.e., mob Ak+1, mob Bk+1).Also, in order to be carried and transmitted over frequency F1 (#1), themobile service data of the output mass mob Ak+1 are outputted to thefirst group formatter 314. And, in order to be carried and transmittedover frequency F2 (#2), the mobile service data of the output mass mobBk+1 are outputted to the second group formatter 314-1. This process isidentically applied to the mobile service data of each MPH frame thatare inputted in accordance with the time order. And, when the mobileservice data of two output masses, which are divided from one MPH frame,are scattered and transmitted over two difference frequency channels,the mobile service data of the two output masses may be outputted at thesame time order or outputted at different time orders.

More specifically, referring to FIG. 9( b), two output masses processedat each time order are divided to two different frequency channels andtransmitted in the same transmission unit and cycle period.

Also, even when being scattered by frequency, the diversity processinginformation is modified by the diversity controller 310. Then, suchdiversity processing information is processed by the first and secondgroup formatters 314 and 314-1 as signaling information, thereby beingtransmitted along with the corresponding mobile service data. Morespecifically, the transmission parameter being encoded and outputtedfrom the signaling encoder 317 and the diversity processing informationbeing outputted from the diversity controller 310 are each processed assignaling information by both group formatters 314 and 314-1.

The Pre-Processor of a Third Embodiment

The pre-processor according to the third embodiment to the presentinvention is for scattering the mobile service data on the time andfrequency sections as many times as the diversity degree, therebyoutputting the processed data. More specifically, in the thirdembodiment of the present invention, the mobile service data are encodedat a coding rate of 1/N at each time order. Subsequently, the 1/N-rateencoded mobile service data are scattered to a plurality of timesections and frequency channels corresponding to the diversity degree,thereby being outputted.

In order to disperse and output the mobile service data to time sectionsand frequency sections, the pre-processor according to the thirdembodiment of the present invention may be further provided with adiversity buffer in addition to the structure shown in FIG. 7.

FIG. 8 illustrates a block diagram showing the structure of thepre-processor 230 according to a third embodiment of the presentinvention, wherein the diversity degree is ‘2’.

Referring to FIG. 8, the pre-processor according to the third embodimentof the present invention includes a data randomizer 321, an RS frameencoder 322, a block processor 323, a diversity buffer 324, first andsecond group formatters 325 and 335, first and second datadeinterleavers 326 and 336, first and second packet formatters 327 and337, first and second signaling encoders 328 and 338, and a diversitycontroller 320. Herein, FIG. 9( c) illustrates an example of the mobileservice data being dispersed and transmitted to multiple time sectionsand frequency sections from a structure provided with one blockprocessor and one diversity buffer.

The data randomizer 321 included in the pre-processor randomizes theinputted mobile service data and outputs the randomized data to the RSframe encoder 322. The RS frame encoder 322 performs RS-frame unitencoding and super-frame unit row permutation on the randomized andinputted mobile service data, thereby outputting the processed data tothe block processor 323. The block processor 323 then encodes theinputted mobile service data, which are encoded and outputted from theRS frame encoder 322, once again at a coding rate of 1/N (wherein N isan integer equal to or greater than 2, N≧22). At this point, thediversity controller 320 controls the block processor 323 and thediversity buffer 324 in accordance with the designated diversity degreeand transmission method (for example, a diversity method by time andfrequency), thereby enabling the RS-frame-encoded mobile service datasymbol to be transmitted to different symbol sections by time andfrequency.

More specifically, based upon the control of the diversity controller320, the block processor 323 encodes the inputted mobile service data ata coding rate of 1/N, the 1/N-rate encoded mobile service data aredivided into 2 output masses and outputted to the diversity buffer 324.For example, when the coding rate is ¼ and the diversity degree is ‘2’,and when the scattering (or dispersion) and transmission unit of thedata corresponds to an MPH frame, the block processor 323 encodes theinputted mobile service data of one MPH frame section at a coding rateof ¼. Then, the block processor 323 divides the ¼-rate encoded mobileservice data into two output masses (or groups) (i.e., mob Ak, mob Bk),which are then outputted to the diversity buffer 324. In addition, theblock processor 323 also performs ¼-rate encoding on the mobile servicedata of three MPH frame sections, which are sequentially inputted insuccession to the MPG frame section. Then, the block processor 323divides the ¼-rate encoded mobile service data into two output masses(mob Ak+1, mob Bk+1), (mob Ak+2, mob Bk+2), and (mob Ak+3, mob Bk+3).

The diversity buffer 324 temporarily stores the mobile service data ofeach output mass (mob Ak, mob Bk, mob Ak+1, mob Bk+1, mob Ak+2, mobBk+2, mob Ak+3, mob Bk+3) being outputted from the block processor 323.Thereafter, the diversity buffer 324 outputs the stored data to thefirst and second group formatters 325 and 335 according to a pre-decidedorder. For example, as shown in FIG. 9( c), the mobile service data ofthe corresponding output mass are loaded on four MPH frames by the orderof mob Ak, mob Ak+1, mob Ak+2, and mob Ak+3 and outputted to the firstgroup formatter 325 so as to be transmitted over frequency F1 (#1).Also, the mobile service data of the corresponding output mass areloaded on four MPH frames by the order of mob Bk, mob Bk+1, mob Bk+2,and mob Bk+3 and outputted to the second group formatter 335 so as to betransmitted over frequency F2 (#2).

Since the operations of the first and second group formatters 325 and335 are identical to that of the group formatter 306 shown in FIG. 6, adetailed description of the same will be omitted for simplicity. Theoutput of the first group formatter 325 is inputted to the first datadeinterleaver 326 so as to be deinterleaved, thereby being outputted tothe first packet formatter 327. Also, the output of the second groupformatter 335 is inputted to the second data deinterleaver 336 so as tobe deinterleaved, thereby being outputted to the second packet formatter337.

Similarly, since the operations of the first and second datadeinterleaver 326 and 336 and the first and second packet formatter 327and 337 are identical to the data deinterleaver 307 and to the packetformatter 308 of FIG. 6, detailed description of the same will beomitted for simplicity. Furthermore, the mobile service data of each MPHframe section being outputted from the first and second packet formatter327 and 337 are transmitted to two different frequency channels (i.e.,frequencies F1 and F2) through the packet multiplexer andpost-processor, which are each provided in parallel in correspondencewith the diversity degree value.

Meanwhile, in order to transmit different types of mobile service databy scattering the corresponding data by time and frequency, thepre-processor of FIG. 8 may further include a data randomizer 331, an RSframe encoder 332, a block processor 333, and a diversity buffer 334.FIG. 9( d) illustrates an example of the mobile service data beingdispersed and transmitted to multiple time sections and frequencysections from a structure provided with a plurality of block processors.

More specifically, the first mobile service data pass through the firstdata randomizer 321 and the RS frame encoder 322 so as to be outputtedto the first block processor 323. And, the second mobile service datapass through the second data randomizer 331 and the RS frame encoder 322so as to be outputted to the second block processor 333. Based upon thecontrol of the diversity controller 320, the first block processor 323receives the RS-frame encoded first mobile service data and encodes thereceived first mobile service data at a coding rate of 1/N. Then, the1/N-rate encoded first mobile service data are divided to two outputmasses and, then, outputted to the first diversity buffer 324.Subsequently, based upon the control of the diversity controller 320,the first diversity buffer 324 temporarily stores the mobile servicedata of the two output masses. Then, the stored mobile service data maybe outputted to only one of the first and second group formatters 325and 335, or be outputted to each of the first and second groupformatters 325 and 335.

Similarly, based upon the control of the diversity controller 320, thesecond block processor 333 receives the RS-frame encoded second mobileservice data and encodes the received second mobile service data at acoding rate of 1/N. Then, the 1/N-rate encoded second mobile servicedata are divided to two output masses and, then, outputted to the seconddiversity buffer 334. Subsequently, based upon the control of thediversity controller 320, the second diversity buffer 334 temporarilystores the mobile service data of the two output masses. Then, thestored mobile service data may be outputted to only one of the first andsecond group formatters 325 and 335, or be outputted to each of thefirst and second group formatters 325 and 335.

In the present invention, when the coding rate is ¼, and when thediversity degree is ‘2’, as shown in FIG. 9( d), among the two outputmasses (mob Ak, mob Bk) within the one MPH frame being outputted fromthe first block processor 323, the first diversity buffer 325 accordingto the embodiment of the present invention outputs the mobile servicedata of one output mass mob Ak to the first group formatter 326 so as tobe transmitted over frequency F1 (#1), and then the first diversitybuffer 325 according to the embodiment of the present invention outputsthe mobile service data of the other output mass mob Bk to the secondgroup formatter 336 so as to be transmitted over frequency F2 (#2).Similarly, according to the embodiment of the present invention, amongthe two output masses (mob Ak′, mob Bk′) within the one MPH frame beingoutputted from the second block processor 333, the mobile service dataof one output mass mob Bk′ are outputted to the first group formatter326 so as to be transmitted over frequency F1 (#1), and then the mobileservice data of the other output mass mob Ak′ are outputted to thesecond group formatter 336 so as to be transmitted over frequency F2(#2).

The output of the first group formatter 325 is inputted to the firstdata deinterleaver 326 so as to be deinterleaved. Then, thedeinterleaved data are outputted to the first packet formatter 327.Also, the output of the second group formatter 335 is inputted to thesecond data deinterleaver 336 so as to be deinterleaved. Then, thedeinterleaved data are outputted to the second packet formatter 337.Thereafter, the mobile service data of each MPH frame section beingoutputted from the first and second packet formatters 327 and 337 aretransmitted to two different frequency channels (i.e., frequencies F1and F2) through the packet multiplexer and post-processor, which areeach provided in parallel in correspondence with the diversity degreevalue.

Meanwhile, even when being scattered by time and by frequency, thediversity processing information is modified by the diversity controller320. Then, such diversity processing information is processed by thefirst and second group formatters 325 and 335 as signaling information,thereby being transmitted along with the corresponding mobile servicedata. More specifically, the transmission parameter being encoded andoutputted from the first and second signaling encoders 328 and 338 andthe diversity processing information being outputted from the diversitycontroller 320 are each processed as signaling information by both groupformatters 325 and 335.

Block Processor

FIG. 10 illustrates a block diagram showing the structure of a blockprocessor according to an embodiment of the present invention. The blockprocessor shown in FIG. 10 may be applied as the block processoraccording to the first to third embodiments of the present invention.The block processor of FIG. 10 includes a byte-bit converter 401, asymbol encoding unit 402, a symbol interleaving unit 403, and asymbol-byte converting unit 404. Herein, the byte-bit converter 401distinguishes the mobile service data bytes being RS-frame encoded andinputted and, then, outputs the distinguished data bytes to the symbolencoding unit 402. The symbol encoding unit 402 encoded the inputtedmobile service data at a coding rate of 1/N. Thereafter, the 1/N-rateencoded mobile service data are divided into a plurality of outputmasses.

For example, when it is assumed that the diversity degree is ‘2’, andthat the mobile service data are scattered in the time section, thesymbol encoding unit 402 divides the 1/N-rate encoded mobile servicedata to two output masses. The symbol interleaving unit 403 is providedwith a number of symbol interleavers corresponding to the number ofdivided output masses. Then, each symbol interleaver performs blockinterleaving in symbol units on the mobile service data of thecorresponding output mass. Any interleaver that can structurally performorder realignment may be applied as the symbol interleaver. The outputend of each symbol interleaver is connected to the symbol-byteconverter. More specifically, the symbol-byte converting unit 404includes as many symbol-byte converters as the number of symbolinterleavers included in the symbol interleaving unit 403. Herein, eachsymbol-byte converter converts symbol data being interleaved andoutputted from the respective symbol interleaver, thereby outputting theprocessed data. More specifically, since 2 bits configure 1 symbol, 4symbols are grouped to form 1 byte.

At this point, when the mobile service data are scattered in the timesection, the output data of multiple symbol-byte converters are providedto the diversity buffer. Conversely, when the mobile service data arescattered in the frequency section, the output data of each symbol-byteconverter are provided to the respective group formatter. Morespecifically, by receiving 1 bit and encoding the received 1 bit to Nnumber of bits, the symbol encoding unit 402 included in the blockprocessor may generate an output of N bits. Also, the N bits may bedivided into a plurality of output masses based upon the diversitydegree, which are then independently processed by the respective symbolinterleaver and symbol-byte converter.

As described above, the detailed structure of the symbol encoding unit402 may vary depending upon the coding rate, the diversity degree, andthe scattering (or dispersion) by time and/or frequency. Also, thenumber of symbol interleavers in the symbol interleaving unit 403 andthe number of symbol-byte converters in the symbol-byte converting unit404 may also vary depending upon the structure of the symbol encodingunit 402.

FIG. 11A and FIG. 11B respectively illustrate block views showingexemplary structures for encoding mobile service data at a coding rateof ¼ and dividing the ¼-rate encoded mobile service data into two outputmasses, thereby respectively performing symbol interleaving.

Referring to FIG. 11A, a ½-encoder 411 and a symbol repeater 412correspond to the symbol encoding unit 402, and first and second symbolinterleavers 413 and 414 correspond to the symbol interleaving unit 403.

More specifically, the ½-encoder 411 encodes the inputted mobile servicedata bit at a coding rate of ½, thereby outputting the ½-rate encodedmobile service data bit to the symbol repeater 412. For example, when1*L bits of mobile service data are encoded at the coding rate of ½, 2*Lbits of mobile service data are outputted to the symbol repeater 412.When the 2*L bits of mobile service data are repeated by the symbolrepeater 412, 4*L bits of mobile service data may be obtained. Morespecifically, the ½-encoder 411 and the symbol repeater 412 may becombined to perform the function of a ¼-encoder.

At this point, the symbol repeater 412 outputs 2*L bits among the 4*Lbits of mobile service data to the first symbol interleaver 413 and,then, outputs the remaining 2*L bits of mobile service data to thesecond symbol interleaver 414. For example, if the symbol repeater 412repeats 2*L bits of mobile service data in symbol units, the original(or initial) mobile service data symbol may be outputted to the firstsymbol interleaver 413, and the repeated mobile service data symbol maybe outputted to the second symbol interleaver 414, and vice versa.

Each of the first and second symbol interleavers 413 and 414 performsblock interleaving in symbol units on the respective inputted mobileservice data, thereby outputting the processed data to the respectivesymbol-byte converter (not shown). At this point, the output of thefirst symbol interleaver 413 corresponds to one output mass mob A, andthe output of the second symbol interleaver 414 corresponds to anotheroutput mass mob B. More specifically, the mobile service data encoded atthe coding rate of ¼ are divided into two output masses of the mobileservice data being encoded at the coding rate of ½.

Meanwhile, FIG. 11B illustrates an example, wherein the symbol encodingunit 402 is configured of a ¼-encoder 421, and wherein the symbolinterleaving unit 403 is configured of first and second symbolinterleavers 422 and 423. More specifically, the ¼-encoder 421 encodesthe inputted mobile service data bit at a coding rate of ¼. For example,when 1*L bits of mobile service data are encoded at the coding rate of¼, 4*L bits of mobile service data may be obtained. At this point, the¼-encoder 421 outputs 2*L bits among the 4*L bits of mobile service datato the first symbol interleaver 422 and, then, outputs the remaining 2*Lbits of mobile service data to the second symbol interleaver 423. Forexample, the upper 2*L bits of mobile service data may be outputted tothe first symbol interleaver 422, and the lower 2*L bits of mobileservice data may be outputted to the second symbol interleaver 423.However, this is merely exemplary, and other combinations may be appliedherein.

Each of the first and second symbol interleavers 422 and 423 performsblock interleaving in symbol units on the respective inputted mobileservice data, thereby outputting the processed data to the respectivesymbol-byte converter (not shown). At this point, the output of thefirst symbol interleaver 422 corresponds to one output mass mob A, andthe output of the second symbol interleaver 423 corresponds to anotheroutput mass mob B. Similarly, the mobile service data encoded at thecoding rate of ¼ are divided into two output masses of the mobileservice data being encoded at the coding rate of ½.

FIG. 12A and FIG. 12B respectively illustrate block views showingexemplary structures for encoding mobile service data at a coding rateof ⅙ and dividing the ⅙-rate encoded mobile service data into two outputmasses, thereby respectively performing symbol interleaving.

Referring to FIG. 12A, a ⅓-encoder 431 and a symbol repeater 432correspond to the symbol encoding unit 402, and first and second symbolinterleavers 433 and 434 correspond to the symbol interleaving unit 403.

More specifically, the ⅓-encoder 431 encodes the inputted mobile servicedata bit at a coding rate of ⅓, thereby outputting the ⅓-rate encodedmobile service data bit to the symbol repeater 432. For example, when1*L bits of mobile service data are encoded at the coding rate of ⅓, 3*Lbits of mobile service data are outputted to the symbol repeater 432.When the 3*L bits of mobile service data are repeated by the symbolrepeater 432, 6*L bits of mobile service data may be obtained. Morespecifically, the ⅓-encoder 431 and the symbol repeater 432 may becombined to perform the function of a ⅙-encoder.

At this point, the symbol repeater 432 outputs 3*L bits among the 6*Lbits of mobile service data to the first symbol interleaver 433 and,then, outputs the remaining 3*L bits of mobile service data to thesecond symbol interleaver 434. For example, if the symbol repeater 432repeats 3*L bits of mobile service data in symbol units, the original(or initial) mobile service data symbol may be outputted to the firstsymbol interleaver 433, and the repeated mobile service data symbol maybe outputted to the second symbol interleaver 434, and vice versa.

Each of the first and second symbol interleavers 433 and 434 performsblock interleaving in symbol units on the respective inputted mobileservice data, thereby outputting the processed data to the respectivesymbol-byte converter (not shown). At this point, the output of thefirst symbol interleaver 433 corresponds to one output mass mob A, andthe output of the second symbol interleaver 434 corresponds to anotheroutput mass mob B. More specifically, referring to FIG. 12A, the mobileservice data encoded at the coding rate of ⅙ are divided into two outputmasses of the mobile service data being encoded at the coding rate of ⅓.

Meanwhile, FIG. 12B illustrates an example, wherein the symbol encodingunit 402 is configured of a ⅙-encoder 441, and wherein the symbolinterleaving unit 403 is configured of first and second symbolinterleavers 442 and 443.

More specifically, the ⅙-encoder 441 encodes the inputted mobile servicedata bit at a coding rate of ⅙. For example, when 1*L bits of mobileservice data are encoded at the coding rate of ⅙, 6*L bits of mobileservice data may be obtained. At this point, the ⅙-encoder 441 outputs3*L bits among the 6*L bits of mobile service data to the first symbolinterleaver 442 and, then, outputs the remaining 3*L bits of mobileservice data to the second symbol interleaver 443. For example, theupper 3*L bits of mobile service data may be outputted to the firstsymbol interleaver 442, and the lower 3*L bits of mobile service datamay be outputted to the second symbol interleaver 443. However, this ismerely exemplary, and other combinations may be applied herein.

Each of the first and second symbol interleavers 442 and 443 performsblock interleaving in symbol units on the respective inputted mobileservice data, thereby outputting the processed data to the respectivesymbol-byte converter (not shown). At this point, the output of thefirst symbol interleaver 442 corresponds to one output mass mob A, andthe output of the second symbol interleaver 443 corresponds to anotheroutput mass mob B. Similarly, referring to FIG. 12B, the mobile servicedata encoded at the coding rate of ⅙ are divided into two output massesof the mobile service data being encoded at the coding rate of ⅓.

According to an embodiment of the present invention, when any one of theblock processors shown in FIG. 11A to FIG. 12B is applied to the blockprocessor 303 shown in FIG. 6, the mobile service data of the outputmass mob A and the mobile service data of the output mass mob B areoutputted to the diversity buffer 304.

According to another embodiment of the present invention, when any oneof the block processors shown in FIG. 11A to FIG. 12B is applied to theblock processor 313 shown in FIG. 7, the mobile service data of theoutput mass mob A are outputted to the first group formatter 314, andthe mobile service data of the output mass mob B are outputted to thesecond group formatter 314-1, and vice versa.

According to yet another embodiment of the present invention, when anyone of the block processors shown in FIG. 11A to FIG. 12B is applied tothe block processor 323 shown in FIG. 8, the mobile service data of theoutput mass mob A are outputted to the first group formatter 325 throughthe diversity buffer 324, and the mobile service data of the output massmob B are outputted to the second group formatter 335 through thediversity buffer 324, and vice versa.

The above-described embodiments shown in FIG. 11A to FIG. 12B correspondto the block processor when the diversity degree is ‘2’. Similarly, whenthe diversity degree is ‘3’, and when the ⅙-encoder is used, the mobileservice data encoded at the coding rate of ⅙ may be divided into 3output masses of ½-rate encoded mobile service data, which are thenscattered by time and/or by frequency. If the diversity degree is ‘3’,and when a ½-encoder, a ⅓-encoder, a ¼-encoder, or a ⅕-encoder is used,the symbol repeater may be used to repeat the input symbol, therebydividing the corresponding mobile service data to 3 output massesencoded at a coding rate of ½.

FIG. 13A illustrates a detailed block diagram of a ½-encoder accordingto an embodiment of the present invention. Referring to FIG. 13A, the½-encoder includes two delay units 501 and 503 and one adder 502.Herein, the ½-encoder encodes an input data bit U and outputs the codedbit U to 2 bits (u0 and u1). At this point, the data bit U is directlyoutputted as an upper bit u0 and simultaneously encoded as a lower bitu1 and then outputted.

More specifically, the input data bit U is directly outputted as theupper bit u0 and simultaneously outputted to the adder 502. The adder502 adds the input data bit U and the output bit of the first delay unit501 and, then, outputs the added bit to the second delay unit 503.Thereafter, the data bit delayed by a pre-determined time (e.g., by 1clock) in the second delay unit 503 is outputted as lower bit u1 andsimultaneously fed-back to the first delay unit 501. The first delayunit 501 delays the data bit fed-back from the second delay unit 503 bya pre-determined time (e.g., by 1 clock). Then, the first delay unit 501outputs the delayed data bit to the adder 502.

FIG. 13B illustrates a detailed block diagram of a ¼-encoder accordingto an embodiment of the present invention. Referring to FIG. 13B, the¼-encoder includes two delay units 501 and 503 and three adders 502,504, and 505. Herein, the ¼-encoder encodes an input data bit U andoutputs the coded bit U to 4 bits (u0 to u3). At this point, the databit U is directly outputted as uppermost bit u0 and simultaneouslyencoded as lower bit u1 u 2 u 3 and then outputted.

More specifically, the input data bit U is directly outputted as theuppermost bit u⁰ and simultaneously outputted to the first and thirdadders 502 and 505. The first adder 502 adds the input data bit U andthe output bit of the first delay unit 501 and, then, outputs the addedbit to the second delay unit 503.

Thereafter, the data bit delayed by a pre-determined time (e.g., by 1clock) in the second delay unit 503 is outputted as lower bit u1 andsimultaneously fed-back to the first delay unit 501. The first delayunit 501 delays the data bit fed-back from the second delay unit 503 bya pre-determined time (e.g., by 1 clock). Then, the first delay unit 501outputs the delayed data bit to the first adder 502 and the second adder504. The second adder 504 adds the data bits outputted from the firstand second delay units 501 and 503 as a lower bit u2. The third adder505 adds the input data bit U and the output of the second delay unit503 and outputs the added data bit as a lower bit u3.

FIG. 14 illustrates a block diagram showing the structure of a ⅕-encoderaccording to an embodiment of the present invention. The overallelements of the ⅕-encoder are identical to those of the ¼-encoder shownin FIG. 13B. However, the difference between the encoder of FIG. 14 andthe encoder of FIG. 13B is that, in FIG. 14, the lowermost bit u4 isdirectly outputted without modification as the output of the first delayunit 501.

Also, when it is assumed that a ⅕-encoder shown in FIG. 14 is used asthe symbol encoding unit 402, part of the output bits of the ⅕-encodermay be grouped so as to be divided into a plurality of output masses.For example, part of the data bits outputted from the ⅕-encoder may begrouped by 2 bits, thereby dividing the ⅕-rate encoded mobile servicedata to 2 output masses having the coding rate of ½. For example, asymbol may be configured of output bits u0 u 1 so as to be outputted tothe output mass mob A, and a symbol may be configured of output bits u3u 4 so as to be outputted to the output mass mob B. In another example,a symbol may be configured of output bits u0 u 2 so as to be outputtedto the output mass mob A, and a symbol may be configured of output bitsu1 and u4 so as to be outputted to the output mass mob B.

Meanwhile, when the coding rate, i.e., N, of the symbol encoding unit402 is an integer cannot be divided by the diversity degree, based uponthe coding method, the N-bit output with respect to a 1-bit input may berepeated so as to obtain an output of 2N bits or 3N bits. Thereafter,the obtained bits may be divided so as to be grouped into masses,thereby being independently processed. At this point, a method ofbreaking down (or dividing) the output of an encoder so as to form amass may be used in all cases where each mass has the same number ofbits included therein.

As described above, after having the symbol encoding unit 402 encode themobile service data at a coding rate of 1/N, and after having the1/N-rate encoded mobile service data divided into a plurality of outputmasses, each output mass is interleaved by an independent symbolinterleaver. More specifically, when the 1/N-rate encoded mobile servicedata are divided into 2 output masses, each output mass of thecorresponding mobile service data is block interleaved in symbol unitsthrough two independent symbol interleavers.

At this point, any interleaver that can structurally perform orderrealignment may be applied as the symbol interleaver. In the presentinvention, even when the symbol that is to have its order realigned hasdifferent lengths, an example of using an applicable variable lengthsymbol interleaver will be described according to the embodiment of thepresent invention. Also, for the interleaving unit, an M*L sizebit-interleaving process may be used on a bit symbol having the lengthof L, or an L size symbol interleaving process may be used on an M-bitsymbol unit.

FIG. 15( a) to FIG. 15( c) illustrate a symbol interleaver according toan embodiment of the present invention. Herein, the symbol interleaveraccording to the embodiment of the present invention corresponds to avariable length symbol interleaver that may be applied even when aplurality of lengths is provided for the symbol, so that its order maybe rearranged. Namely, FIG. 15( a) to FIG. 15( c) is a detaileddescription for any one symbol interleaver of a plurality of symbolinterleavers within the symbol interleaving unit 403.

Particularly, FIG. 15( a) to FIG. 15( c) illustrate an example of thesymbol interleaver when BK=6 and BL=8. Herein, BK indicates a number ofsymbols that are outputted for symbol interleaving from thecorresponding output mass among the plurality of output masses of thesymbol encoding unit 402. And, BL represents a number of symbols thatare actually interleaved by the symbol interleaver.

In the present invention, the symbol interleaving unit 403 shouldsatisfy the conditions of BL=2^(n) (wherein n is an integer) and ofBL≧BK. If there is a difference in value between BK and BL, (BL−BK)number of null (or dummy) symbols is added, thereby creating aninterleaving pattern. Therefore, BK becomes a block size of the actualsymbols that are inputted to the symbol interleaving unit 403 in orderto be interleaved. BL becomes an interleaving unit when the interleavingprocess is performed by an interleaving pattern created from the symbolinterleaving unit 403.

The example of what is described above is illustrated in FIG. 15( a) toFIG. 15( c). The number of symbols outputted from the correspondingoutput mass of the symbol encoding unit 402 in order to be interleavedis equal to 6 (i.e., BK=6). In other words, 6 symbols are outputted fromthe symbol encoding unit 402 in order to be interleaved. And, the actualinterleaving unit (BL) is equal to 8 symbols. Therefore, as shown inFIG. 15( a), 2 symbols are added to the null (or dummy) symbol, therebycreating the interleaving pattern.

Equation 1 shown below described the process of sequentially receivingBK number of symbols, the order of which is to be rearranged, andobtaining an BL value satisfying the conditions of BL=2^(n) (wherein nis an integer) and of BL≧BK, thereby creating the interleaving so as torealign (or rearrange) the symbol order.

Equation 1

In relation to all places, wherein 0≦i≦BL−1,

P(i)={S×i×(i+1)/2} mod BL

Herein, BL≧BK, BL=2^(n), and n and S are integers. FIG. 15 shows anexample of an interleaving pattern and an interleaving process, whereinit is assumed that S is equal to 89, and that BL is equal to 8.

As shown in FIG. 15( b), the order of BK number of input symbols and(BL−BK) number of null symbols is rearranged by using theabove-mentioned Equation 1. Then, as shown in FIG. 15( c), the null byteplaces are removed, so as to rearrange the order, by using Equation 2shown below. Thereafter, the symbol that is interleaved by therearranged order is then outputted to the corresponding symbol-byteconverter of the symbol-byte converting unit 404.

if P(i)>BK−1,  Equation 2

then P(i) place is removed and rearranged

Subsequently, the symbol-byte converter converts to bytes the mobileservice data symbols, having the rearranging of the symbol ordercompleted and then outputted in accordance with the rearranged orderfrom the corresponding symbol interleaver, and thereafter outputs theconverted bytes to the corresponding group formatter (or diversitybuffer). For example, when mobile service data is scattered into timesections, the output of the symbol converter is outputted to thediversity buffer. Also, when mobile service data is scattered intofrequency sections, the output of the symbol converter is outputted tothe corresponding group formatter.

The operation of the group formatter, data deinterleaver, and packetformatter within the pre-processor 230 according to the presentinvention was described in detail above. Therefore, a detaileddescription of the same will be omitted for simplicity.

The output of the packet formatter in the pre-processor 230 is inputtedto the packet multiplexer 240.

The packet multiplexer 240 multiplexes the data group packet-formattedand outputted from the packet formatter 308 and the main service datapacket outputted from the packet jitter mitigator 220 in accordance witha pre-defined multiplexing method. Then, the packet multiplexer 240outputs the multiplexed data packets to the data randomizer of thepost-processor 250. The multiplexing method and multiplexing rules ofthe packet multiplexer 240 will be described in more detail in a laterprocess.

Also, since a data group including mobile service data in-between thedata bytes of the main service data is multiplexed (or allocated) duringthe packet multiplexing process, the shifting of the chronologicalposition (or place) of the main service data packet becomes relative.Also, a system object decoder (i.e., MPEG decoder) for processing themain service data of the receiving system, receives and decodes only themain service data and recognizes the mobile service data packet as anull data packet. Therefore, when the system object decoder of thereceiving system receives a main service data packet that is multiplexedwith the data group, a packet jitter occurs.

At this point, since a multiple-level buffer for the video data existsin the system object decoder and the size of the buffer is relativelylarge, the packet jitter generated from the packet multiplexer 240 doesnot cause any serious problem in case of the video data. However, sincethe size of the buffer for the audio data in the object decoder isrelatively small, the packet jitter may cause considerable problem.

More specifically, due to the packet jitter, an overflow or underflowmay occur in the buffer for the main service data of the receivingsystem (e.g., the buffer for the audio data).

Therefore, the packet jitter mitigator 220 re-adjusts the relativeposition of the main service data packet so that the overflow orunderflow does not occur in the system object decoder.

In the present invention, examples of repositioning places for the audiodata packets within the main service data in order to minimize theinfluence on the operations of the audio buffer will be described indetail. The packet jitter mitigator 220 repositions the audio datapackets in the main service data section so that the audio data packetsof the main service data can be as equally and uniformly aligned andpositioned as possible.

Additionally, when the positions of the main service data packets arerelatively re-adjusted, associated program clock reference (PCR) valuesmay also be modified accordingly. The PCR value corresponds to a timereference value for synchronizing the time of the MPEG decoder. Herein,the PCR value is inserted in a specific region of a TS packet and thentransmitted.

In the example of the present invention, the packet jitter mitigator 220also performs the operation of modifying the PCR value. The output ofthe packet jitter mitigator 220 is inputted to the packet multiplexer240. As described above, the packet multiplexer 240 multiplexes the mainservice data packet outputted from the packet jitter mitigator 220 withthe mobile service data packet outputted from the pre-processor 230 inaccordance with a pre-determined multiplexing rule. Then, the packetmultiplexer 240 outputs the multiplexed data packets to thepost-processor 250.

Referring to FIG. 25, the post-processor 250 may include a datarandomizer 601, an RS encoder/non-systematic RS encoder 602, a datainterleaver 603, a parity replacer 604, a non-systematic RS encoder 605,and a trellis encoding module 606. When mobile service data is scatteredand transmitted on the frequency section, in order to processindependently mobile service data by each frequency, the post-processorwithin the transmitter should be provided in parallel as many times asthe diversity degree value. FIG. 25 illustrates an exemplary of thetransmitter when mobile service data is scattered and processed on thetime section.

If the inputted data correspond to the main service data packet, thedata randomizer 601 performs the same randomizing process as that of theconventional randomizer. More specifically, the synchronization bytewithin the main service data packet is deleted. Then, the remaining 187data bytes are randomized by using a pseudo random byte generated fromthe data randomizer 601. Thereafter, the randomized data are outputtedto the RS encoder/non-systematic RS encoder 602.

On the other hand, if the inputted data correspond to the mobile servicedata packet, the data randomizer 601 may randomize only a portion of thedata packet. For example, if it is assumed that a randomizing processhas already been performed in advance on the mobile service data packetby the pre-processor 230, the data randomizer 601 deletes thesynchronization byte from the 4-byte MPEG header included in the mobileservice data packet and, then, performs the randomizing process only onthe remaining 3 data bytes of the MPEG header. Thereafter, therandomized data bytes are outputted to the RS encoder/non-systematic RSencoder 602. More specifically, the randomizing process is not performedon the remaining portion of the mobile service data excluding the MPEGheader. In other words, the remaining portion of the mobile service datapacket is directly outputted to the RS encoder/non-systematic RS encoder602 without being randomized. Also, the data randomizer 601 may or maynot perform a randomizing process on the known data (or known data placeholders) and the initialization data place holders included in themobile service data packet.

The RS encoder/non-systematic RS encoder 602 performs an RS encodingprocess on the data being randomized by the data randomizer 601 or onthe data bypassing the data randomizer 601, so as to add 20 bytes of RSparity data. Thereafter, the processed data are outputted to the datainterleaver 603. Herein, if the inputted data correspond to the mainservice data packet, the RS encoder/non-systematic RS encoder 602performs the same systematic RS encoding process as that of theconventional broadcasting system, thereby adding the 20-byte RS paritydata at the end of the 187-byte data. Alternatively, if the inputteddata correspond to the mobile service data packet, the RSencoder/non-systematic RS encoder 602 performs a non-systematic RSencoding process. At this point, the 20-byte RS parity data obtainedfrom the non-systematic RS encoding process are inserted in apre-decided parity byte place within the mobile service data packet.

The data interleaver 603 corresponds to a byte unit convolutionalinterleaver.

The output of the data interleaver 603 is inputted to the parityreplacer 604 and to the non-systematic RS encoder 605.

Meanwhile, a process of initializing a memory within the trellisencoding module 606 is primarily required in order to decide the outputdata of the trellis encoding module 606, which is located after theparity replacer 604, as the known data pre-defined according to anagreement between the receiving system and the transmitting system. Morespecifically, the memory of the trellis encoding module 606 should firstbe initialized before the received known data sequence istrellis-encoded. At this point, the beginning portion of the known datasequence that is received corresponds to the initialization data placeholder and not to the actual known data. Herein, the initialization dataplace holder has been included in the data by the group formatter withinthe pre-processor 230 in an earlier process. Therefore, the process ofgenerating initialization data and replacing the initialization dataplace holder of the corresponding memory with the generatedinitialization data are required to be performed immediately before theinputted known data sequence is trellis-encoded.

Additionally, a value of the trellis memory initialization data isdecided and generated based upon a memory status of the trellis encodingmodule 606. Further, due to the newly replaced initialization data, aprocess of newly calculating the RS parity and replacing the RS parity,which is outputted from the data interleaver 603, with the newlycalculated RS parity is required. Therefore, the non-systematic RSencoder 605 receives the mobile service data packet including theinitialization data place holders, which are to be replaced with theactual initialization data, from the data interleaver 603 and alsoreceives the initialization data from the trellis encoding module 606.

Among the inputted mobile service data packet, the initialization dataplace holders are replaced with the initialization data, and the RSparity data that are added to the mobile service data packet are removedand processed with non-systematic RS encoding. Thereafter, the new RSparity obtained by performing the non-systematic RS encoding process isoutputted to the parity replacer 604. Accordingly, the parity replacer604 selects the output of the data interleaver 603 as the data withinthe mobile service data packet, and the parity replacer 604 selects theoutput of the non-systematic RS encoder 605 as the RS parity. Theselected data are then outputted to the trellis encoding module 606.

Meanwhile, if the main service data packet is inputted or if the mobileservice data packet, which does not include any initialization dataplace holders that are to be replaced, is inputted, the parity replacer604 selects the data and RS parity that are outputted from the datainterleaver 603. Then, the parity replacer 604 directly outputs theselected data to the trellis encoding module 606 without anymodification.

The trellis encoding module 606 converts the byte-unit data to symbolunits and performs a 12-way interleaving process so as to trellis-encodethe received data. Thereafter, the processed data are outputted to thesynchronization multiplexer 260.

The synchronization multiplexer 260 inserts a field synchronizationsignal and a segment synchronization signal to the data outputted fromthe trellis encoding module 606 and, then, outputs the processed data tothe pilot inserter 271 of the transmission unit 270. Herein, the datahaving a pilot inserted therein by the pilot inserter 271 are modulatedby the modulator 272 in accordance with a pre-determined modulatingmethod (e.g., a VSB method). Thereafter, the modulated data aretransmitted to each receiving system though the radio frequency (RF)up-converter 273.

Multiplexing Method of a Packet Multiplexer 240

Meanwhile, the packet multiplexer 240 a data group is allocated to a VSBframe based upon a starting point of a slot. Also, main service data areallocated in-between data groups, thereby performing the multiplexingprocess. According to an embodiment of the present invention, based upona data structure prior to data interleaving, data are allocated to astarting point of a slot (i.e., a first data segment of the slot)starting from the N^(th) packet of the data group. Herein, N is aninteger. Also, the value N has a different meaning from the N used inthe block processor within the pre-processor 230. For example, when N=1,the data starting from the 1^(st) packet of the corresponding data groupare allocated to a 1^(st) data segment of the current slot. And, whenN=38, the data starting from the 38^(th) packet of the correspondingdata group are allocated to a 1^(st) data segment of the current slot.If N=1, one data group may be allocated to one slot.

FIG. 17 illustrates an example of a 38^(th) packet of a correspondingdata group data being allocated to a starting point of a slot (i.e., thefirst data segment of the current slot), based upon a data structureprior to data interleaving. In this case, the portion starting from the1^(st) packet to the 37^(th) packet of the corresponding data group isallocated to the previous slot. Also, as shown in FIG. 17, when it isassumed that a data group is allocated to each slot with the VSB frame,a synchronization multiplexer 260 may insert a field synchronizationsignal after the 37^(th) packet of the data group being allocated to the1^(st) slot of each field. In this case, the receiving system may alsouse the field synchronization for channel equalization, therebyenhancing the receiving performance of the corresponding data group.

As described above, after being encoded at a coding rate of 1/N by theblock processor, the data of one RS frame is divided into a plurality ofoutput masses based upon the diversity degree. Then, the plurality ofoutput masses divided as described above may be outputted to the samegroup formatter at different time periods (ref. FIG. 6), and theplurality of output masses may also be outputted to each group formatterso as to be transmitted through different frequencies (ref. FIG. 7 andFIG. 8). The data of each output mass are distributed to a plurality ofdata groups by the corresponding group formatter, thereby beingallocated to the respective region. Such data group passes through thedata deinterleaver and packer formatter each connected to thecorresponding group formatter, so as to be multiplexed with the mainservice data by the packet multiplexer 240 in accordance with apre-decided multiplexing rule.

In the description of the present invention, the plurality of datagroups having data within an output mass assigned (or allocated) theretowill be referred to as an “ensemble”.

According to an embodiment of the present invention, the data groupsincluded in an ensemble are allocated to be spaced apart from oneanother as possible within the MPH frame. Thus, the system can becapable of responding promptly and effectively to any burst error thatmay occur within an ensemble.

Additionally, since the data groups for each ensemble are allocatedbased upon the MPH frames, the method for allocating the data groups mayvary depending upon the corresponding MPH frame. Furthermore, the datagroups are equally (or identically) allocated to each sub-frame withinan MPH frame.

According to the embodiment of the present invention, in each sub-frame,the data groups are serially allocated to a group space having 4 slots(i.e., 1 VSB frame) from left to right. Therefore, a number of groups ofone ensemble per sub-frame (NOG) may correspond to any one integer from‘1’ to ‘8’. Herein, since one MPH frame includes 5 sub-frames, the totalnumber of data groups within an ensemble that can be allocated to an MPHframe may correspond to any one multiple of ‘5’ ranging from ‘5’ to‘40’.

FIG. 18 illustrates an example of multiple data groups of a singleensemble being allocated (or assigned) to an MPH frame. Morespecifically, FIG. 18 illustrates an example of a plurality of datagroups included in an ensemble having an NOG of ‘3’ being allocated toan MPH frame.

Referring to FIG. 18, 3 data groups are sequentially assigned to asub-frame at a cycle period of 4 slots. Accordingly, when this processis equally performed in the 5 sub-frames included in the correspondingMPH frame, 12 data groups are assigned to a single MPH frame. Herein,the 15 data groups correspond to data groups included in an ensemble.Therefore, since one sub-frame is configured of 4 VSB frame, and sincethe NOG is equal to ‘3’, the data group of the corresponding ensemble isnot assigned to 1 VSB frame within each sub-frame.

For example, when the RS code mode of a corresponding RS frame is equalto ‘00’ (i.e., when 24 bytes of parity data are added to thecorresponding RS frame by an RS encoding process), the parity dataoccupies approximately 11.37% (=24/(187+24)×100) of the total code wordlength. Meanwhile, when the NOG is equal to ‘3’, and when the datagroups of an ensemble are assigned, as shown in FIG. 18, a total of 15data groups form an RS frame. Accordingly, even when an error occurs inan entire data group due to a burst noise within a channel, thepercentile is merely 6.67% (=1/15×100). Therefore, all errors may becorrected by an erasure RS decoding process. More specifically, when theerasure RS decoding is performed, a number of channel errorscorresponding to the number of RS parity bytes may be corrected. Bydoing so, the receiving system may correct the error of at least onedata group within one ensemble. On the other hand, for example, when thesame information is transmitted as diversity to two MPH frames, even ifan error occurs in all groups within one of the two received MPH frames,and if 11.37% of error occurs in the remaining MPH frame, the error canbe corrected. Therefore, errors existing in at least 16 data groups maybe corrected.

Meanwhile, when data groups of an ensemble are assigned as describedabove, either main service data may be assigned between each data group,or data groups corresponding to different ensembles may be assignedbetween each data group. More specifically, data groups corresponding tomultiple ensembles may be assigned to one MPH frame.

Basically, the method of assigning data groups corresponding to multipleensembles is very similar to the method of assigning data groupscorresponding to a single ensemble.

In other words, data groups included in other ensembles that are to beassigned to an MPH frame are also respectively assigned according to acycle period of 4 slots. At this point, a data group of a differentensemble may be sequentially assigned to a sub-frame starting from the1^(st) VSB frame (i.e., VSB frame 1). Alternatively, a data group of aprevious ensemble may be assigned in a circular method starting from aVSB frame to which a data group has not yet been assigned. For example,when it is assumed that data groups corresponding to an ensemble areassigned as shown in FIG. 18, data groups corresponding to the nextensemble may be assigned to a sub-frame starting either from the 1^(st)VSB frame (VSB frame 1) or the 4^(th) VSB frame (VSB frame 4).

FIG. 19 illustrates an example of allocating data groups for a pluralityof ensembles to one MPH frame. More specifically, FIG. 19 shows anexample of data groups of a 1^(st) ensemble having an NOG of ‘3’ anddata groups of a 2^(nd) ensemble having an NOG of ‘4’ being allocated tothe MPH frame.

Referring to FIG. 19, when the allocation of the data groups to the1^(st) ensemble is completed, the data group of the 2^(nd) ensemble isallocated starting from the 4^(th) VSB frame of the 1^(st) sub-framewithin the corresponding MPH frame. More specifically, the 1^(st) datagroup of the 2^(nd) ensemble may be allocated to the 4^(th) VSB frame ofthe 1^(st) sub-frame, the 2^(nd) data group may be allocated to the1^(st) VSB frame of the 1^(st) sub-frame, the 3^(rd) data group may beallocated to the 2^(nd) VSB frame of the 1^(st) sub-frame, and the4^(th) data group may be allocated to the 3^(rd) VSB frame of the 1^(st)sub-frame. Similarly, the data groups of the 2^(nd) ensemble are alsoallocated in the sub-frames subsequent to the 1^(st) sub-frame. Morespecifically, in FIG. 19, the group number corresponds to an allocatingorder of the data groups in each sub-frame.

At this point, the allocating order of the data groups in one VSB framecorresponds to the 1^(st) slot, the 3^(rd) slot, the 2^(nd) slot, andthe 4^(th) slot.

For example, when four data groups are sequentially allocated to the1^(st) slot of the 4 VSB frame within one sub-frame, the next four datagroups are sequentially allocated to the 3^(rd) slot of each VSB framewithin one sub-frame. Then, the next four data groups are sequentiallyallocated to the 2^(nd) slot of each VSB frame within one sub-frame.And, finally, the next four data groups are sequentially allocated tothe 4^(th) slot of each VSB frame within one sub-frame.

Therefore, when it is assumed that the above-described process isperformed, and that 16 data groups are allocated to 4 VSB frame within asub-frame, in case of the 1^(st) VSB frame, the 1^(st) data group isallocated to the 1^(st) slot, the 5^(th) data group is allocated to the3^(rd) slot, the 9^(th) data group is allocated to the 2^(nd) slot, andthe 13^(th) slot is allocated to the 4^(th) slot.

Meanwhile, when it is assumed that the minimum number of data groupsthat can be allocated to one sub-frame for one ensemble is equal to ‘1’,up to a maximum number of 16 different ensembles may be transmitted inone MPH frame. This is because the maximum number of 16 data groups maybe transmitted to a single sub-frame.

The following Equation 3 indicates the above-described multiplexing rule(or allocation rule) of the above-described data group.

SLOT_(i)=((4(i−1)+0_(i))mod 16)+1  Equation 3

-   -   0_(i)=0 if 1≦i≦4,    -   0_(i)=2 else if i≦8,

Herein,

-   -   0_(i)=1 else if i≦12,    -   0_(i)=3 else.

Also, 1≦SLOT_(i)≦16, and 1≦i≦TNOG.

More specifically, SLOT_(i) represents the slot having the i^(th) datagroup allocated thereto within a sub-frame. And, the slot number (i)within the sub-frame has any one of the values ranging from ‘1’ to ‘16’.

And, TNOG represents a total number of groups assigned (or allocated) toall ensembles for one sub-frame.

For example, it is assumed that 2 ensembles are assigned to one MPHframe, and that NOG2 of ensemble 2 is equal to ‘4’ (i.e., NOG2=4).Herein, NOGj represents the number of data groups included in a j^(th)ensemble (ensemble j) of a sub-frame. In this case, within onesub-frame, the data groups of ensemble 1 are assigned to slot 1, slot 5,and slot 9 (wherein, i=1, 2, 3), and the data groups of ensemble 2 areassigned to slot 13, slot 3, slot 7, and slot 11 (wherein, i=4, 5, 6,7).

Herein, a portion of the RS frame corresponding to ensemble 2 may bemapped in a time order to the 3^(rd) data group, the 7^(th) data group,the 11^(th) data group, and the 13^(th) data group. More specifically,when an RS frame is divided and mapped into a plurality of data groups,instead of mapping the RS frame in a slot order, which is decided bysubstituting an integer for the group number (i) in Equation 3, the RSframe is mapped in a time order starting from the closest slot. In otherwords, when the NOG of an ensemble is decided, the position of each slotto which the data groups of a corresponding ensemble are transmittedwithin a sub-frame is also decided. Accordingly, when the RS frame ofthe corresponding ensemble is divided and transmitted to a plurality ofdata groups, the RS frame is mapped and transmitted in a time order ofthe corresponding slots.

Additionally, each sub-frames within the above-described MPH frame, eachVSB frame within each sub-frame, and the rule for multiplexing the datagroups in each slot within each VSB frame may be pre-decided and sharedby the transmitting system and the receiving system. When thetransmitting system transmits to the receiving system NOG information ofall ensembles that are sent to the corresponding MPH frame, thereceiving system can know to which slot the data group of each slot ismapped by using Equation 3. In this case, the group mapping of allensembles can be known. Hereinafter, the information on which slot thedata groups configuring one ensemble are mapped within a sub-frame willbe referred to as an ensemble MAP. However, when the NOG information ofall ensembles are transmitted as signaling information to all datagroups of all ensembles as described above, by receiving the data groupsof an ensemble, thereby receiving the signaling information, it isadvantageous in that the ensemble MAP for all ensembles existing withinthe corresponding MPH frame can be known. However, the disadvantage isthat the signaling information may be transmitted excessively.

One of the methods for minimizing the amount of signaling information isto transmit only the NOG of the corresponding ensemble. However, whentransmitting only the NOG, the ensemble MAP of the correspondingensemble cannot be obtained by using Equation 3. In order to accuratelyobtain the ensemble MAP using Equation 3, not only the NOG but also astarting group number (SGN) of the ensemble should be given. In otherwords, when given the NOG and SGN of the corresponding ensemble, theensemble MAP of the corresponding ensemble can be obtained. Herein, theSGN indicates the number of the data group, which may be substituted byi in Equation 3. More specifically, referring to FIG. 19, the startinggroup number (SGN) of ensemble 2 is equal to ‘4’. This is because theNOG of ensemble 1 is equal to ‘3’ in FIG. 19.

Meanwhile, in order to enable the receiving system to receive only thedata of the desired (or requested) ensemble, the transmitting system isrequired to transmit an identifier for each ensemble (i.e., an ensembleidentifier, hereinafter referred to as “ensemble_id”) to the receivingsystem. Since the maximum number of ensembles that can be transmitted(i.e., the maximum number of transmittable ensembles) within an MPHframe is equal to ‘16’, the ensemble_id may be indicated as 4 bits.

Unlike in real-time data broadcasting, such as audio and video data,channel change time is not as significant (or important) as in non-realtime data broadcasting. Therefore, the data of a particular ensemble isnot required to be transmitted for each MPH frame. Instead, the data maybe transmitted once for each set of multiple MPH frames. For example,data may be transmitted once for each 2 MPH frames. In this case, thedata rate of the corresponding ensemble may be reduced by ½ as comparedto when transmitting data for each MPH frame. Accordingly, when abroadcast station assigns the data rate of an MPH broadcast program, thedata may be provided with smaller resolution, thereby increasing theefficiency in applying broadcast programs. In order to do so, anensemble transmission period (hereinafter referred to as “ETP”) is addedto the signaling information, thereby indicating that the correspondingensemble is transmitted once for k number of MPH frames.

As described above, in order to enable the receiving system to know theensemble MAP of the corresponding ensemble, the transmitting systemtransmits signaling information, such as ensemble_id, SGN, NOG, ETP, andso on, of the corresponding ensemble.

FIG. 21A describes the SGN, wherein SGN is configured of 4 bits. In thiscase, the value of SGN may be equal to any one value ranging from ‘1’ to‘16’. FIG. 21B describes the NOG, wherein NOG is configured of 3 bits.Herein, the value of NOG may be equal to any one value ranging from ‘1’to ‘8’. Furthermore, FIG. 21C describes the ETP, wherein ETP isconfigured of 2 bits. The ETP indicates the MPH frame cycle periodaccording to which the corresponding ensemble is being transmitted.

FIG. 20 illustrates an example of 3 ensembles existing in one MPH frame.Referring to FIG. 20, 3 data groups of the 1^(st) ensemble (E1), 2 datagroups of the 2^(nd) ensemble (E2), and 2 data groups of the 3^(rd)ensemble (E3) exist in one sub-frame. Therefore, in the 1^(st) ensemble,the SGN is equal to ‘1’ (i.e., SGN=1) and the NOG is equal to ‘3’ (i.e.,NOG=3). Also, in the 2^(nd) ensemble, the SGN is equal to ‘4’ (i.e.,SGN=4) and the NOG is equal to ‘2’ (i.e., NOG=2). Similarly, in the3^(rd) ensemble, the SGN is equal to ‘6’ (i.e., SGN=6) and the NOG isequal to ‘2’ (i.e., NOG=2). In FIG. 20, different values may be givenfor the ensemble_id of each ensemble. Also, different values may begiven for the ETP.

Meanwhile, in the receiving system, by turning the power on during asection, wherein the data groups of a requested ensemble are assigned,so as to receive data, and by turning the power off during the remainingsections, excessive power consumption of the receiving system may bereduced. Such characteristic is particularly advantageous in portableand mobile receivers that require low power consumption. For example, itis assumed that data groups of the 1^(st) ensemble with NOG=3 and datagroups of the 2^(nd) ensemble with NOG=2 are assigned to an MPH frame,as shown in FIG. 22( a). It is also assumed that the user uses a keypadprovided on a remote controller or terminal to select a mobile serviceincluded in the 1^(st) ensemble. In this case, the receiving systemturns the power on only during a section having the data groups of the1^(st) ensemble assigned thereto, and turns the power off during theremaining sections, as shown in FIG. 22( b), thereby reducing powerconsumption. At this point, it is preferable that the power is turned onslightly earlier than the section having the actual required dataassigned thereto. This is to enable a tuner or a demodulator to convergein advance.

Processing Signaling Information

Meanwhile, apart from the mobile service data, the group formatter mayalso insert additional (or supplemental) information, such as signalinginformation providing overall (or general) system information, to thedata group. Transmission parameters associated with the transmission andreception of broadcast signals may be determined as the signalinginformation. Herein, the signaling information is encoded based upon apre-determined encoding method by the corresponding signaling encoder,thereby being outputted to the corresponding group formatter. Forexample, the signaling information may include information associatedwith the RS frame and information associated with the MPH frame (ref.,FIG. 21A to FIG. 21C), and so on.

Furthermore, the signaling information may include diversity processinginformation. The diversity processing information may be encoded by thesignaling encoder and, then, outputted to the corresponding groupformatter. Alternatively, the diversity processing information may beencoded by the diversity controller and, then, outputted to thecorresponding group formatter. However, the signaling information ismerely an example proposed to facilitate the understanding of thepresent invention. And, the addition or deletion of the informationincluded in the signaling information may be easily modified by anyoneskilled in the art. Therefore, the present invention will not be limitedto the example given herein.

Referring to FIG. 16A and FIG. 16B, it is apparent that, in the datagroup, a signaling information region for inserting the signalinginformation is assigned to a partial region of the MPH 4 block (B4).

More specifically, referring to the structure of a data group afterbeing processed with data interleaving, as shown in FIG. 16A, it isapparent that 6 known data regions are assigned to the data group inorder to insert known data or known data place holders.

Herein, the 6 known data regions consist of 5 regions for the purpose oftraining the estimation of a channel impulse response (hereinafterreferred to as a “CIR”) (or the purpose of training the channelequalizer) and 1 regions for the purpose of acquiring an initial carrierfrequency synchronization signal.

Referring to FIG. 16A, the 1^(st), 3^(rd), 4^(th), 5^(th), and 6^(th)known data regions correspond to the known data regions assigned for theabove-described purpose of CIR estimation training or channel equalizertraining. Herein, the 1^(st) known data region and 3^(rd) to 6^(th)known data regions may each have relatively different lengths. However,a portion of each known data region has the same pattern value, and eachknown data region is inserted at equal intervals of 16 segments. In theembodiment of the present invention, the known data region is encoded by12 trellis encoders, and the status of each trellis encoder is requiredto be initialized. However, since the regions that can be initializedare pre-decided, it is inevitable to have different lengths for each ofthe 1^(st) known data region and 3^(rd) to 6^(th) known data regions.Nevertheless, once each of the known data regions is initialized, the 5known data patterns are each given the same value starting from apredetermined point to the end of each known data region. Also, each ofthe known data regions is spaced apart at equal intervals.

Meanwhile, the 2^(nd) known data region may be used for acquiring aninitial carrier frequency synchronization signal from the receivingsystem, or for estimating the position of a field synchronization signalor the positions of other known data regions. In order to do so, the2^(nd) known data region is configured of 2 sets of known data havingthe same pattern assigned thereto. In the present invention, theabove-described 1^(st) and 3^(rd) to 6^(th) known data regions may bereferred to as “CIR known data regions”, and the 2^(nd) known dataregion may be referred to as an “ACQ known data region”, wherein ACQstands for “acquisition”.

At this point, the data assigned to the CIR known data regions and theACQ known data region correspond to known data pre-decided based upon anagreement between the transmitting system and the receiving system.Herein, each data group maintains the same pattern. According to theembodiment of the present invention, a signaling region is assignedbetween the 1^(st) known data region and the 2^(nd) known data region.This region may also be referred to as a “signaling information region”.Herein, the data assigned to the signaling information region includesignaling information associated with the corresponding MPH frame,sub-frame, VSB frame, slot, and data group. Therefore, the data maydiffer in each data group.

Referring to FIG. 16A and FIG. 16B, the initialization data regioncorresponds to a region in which trellis memory initialization isperformed in the trellis encoding module.

At this point, the signaling information region may be encoded at acoding rate stronger than ½ or ¼ (e.g., at a coding rate of ⅙ or ⅛),thereby enhancing the receiving performance.

Among the signaling information, the information associated with MPHframes may include sub-frame count information, slot count information,and also information on ensemble_id, SGN, NOG, and ETP, as shown in FIG.23.

Herein, the sub-frame count information and the slot count informationcorrespond to information for the synchronization of one MPH frame. TheSGN and NOG information correspond to information for configuring anensemble MAP (or ensemble MAP information) of the corresponding ensemblein one MPH frame.

The sub-frame count information indicates a counter value designatingthe number of each sub-frame within one MPH frame.

Furthermore, the slot count information indicates a counter valuedesignating the number of each slot within one sub-frame.

Moreover, service or system information may also be transmitted to thesignaling information region. Such information may be used for thepurpose of accelerating service acquisition when the power of thereceiving system is turned on, or when a broadcast service that iscurrently being viewed is changed (or switched). For example,information associated with the service included in each ensemble may betransmitted to the signaling information region. Herein, the informationassociated with the service may include service_id or major and minorchannel numbers. Additionally, a text label for each service (e.g.,short text information of FOX-TV1, WUSA-RADIO, etc.) and detailedinformation (i.e., PID or IP address or port number) on an elementarystream configuring each service may also be included in the informationassociated with the service.

When such information are transmitted from the transmitting system bymeans of the signaling information region, the receiving system maydecode the transmitted information and be informed of the types ofservices existing in the ensemble that is currently being received. Byusing such information, the receiving system may also find (or detect)the ensemble_id corresponding to the ensemble including a requested (ordesired) broadcast service. When the ensemble_id of a requestedbroadcast service is detected, the receiving system may be able toreduce power consumption by receiving only the corresponding ensemble.Herein, the above-described ensemble including the requested broadcastservice may correspond to the ensemble that was most currently received(i.e., the last received ensemble). Furthermore, when an electronicsservice guide (ESG) is transmitted to the signaling information region,the receiving system may be capable of decoding, based upon apre-decided time interval or a request, the signaling informationincluded in data groups corresponding to ensembles other than theensemble that is currently being received, thereby updating the contentsof other services that are to be broadcasted in the future.

FIG. 24( a) to FIG. 24( e) illustrate examples of a signalinginformation scenario being transmitted to the signaling informationregion according to the present invention. More specifically, FIG. 24(a) to FIG. 24( e) respectively illustrate examples of transmittingsignaling information of a current MPH frame, as well as signalinginformation of a future MPH frame, from a current MPH frame section.Referring to FIG. 24, @t represents a current point, and @t+n indicatesa point after n number of MPH frames. Herein, the value of n is decidedby an ETP, which corresponds to a cycle period for transmitting anensemble. Herein, when ETP is equal to ‘00’ (i.e., ETP=00), thisindicates that a corresponding ensemble is transmitted in each MPHframe. Therefore, n is equal to ‘1’ (i.e., n=1). Also, when ETP is equalto ‘01’ (i.e., ETP=01), this indicates that a corresponding ensemble istransmitted in each 2 MPH frames. Therefore, n is equal to ‘2’ (i.e.,n=2). Similarly, when ETP is equal to ‘10’ (i.e., ETP=10), thisindicates that a corresponding ensemble is transmitted in each 3 MPHframes. Therefore, n is equal to ‘3’ (i.e., n=3).

According to the present invention, the above-described signalinginformation may be inserted in the signaling information region of eachdata group assigned to one MPH frame and then transmitted. In this case,the signaling information of a current MPH frame or the signalinginformation of a future MPH frame may be transmitted based upon thesub-frame position. For example, since the sub-frame count informationand the slot count information respectively indicate the positioninformation corresponding to the sub-frame included in the current MPHframe and the position information corresponding to the slot included inthe current sub-frame, the sub-frame count information and the slotcount information of the current point are transmitted from allsub-frame sections.

Furthermore, ensemble MAP information, such as SGN and NOG information,may vary in ensemble units and the data group of each ensemble isequally divided and assigned to 5 sub-frames. Therefore, the ensembleMAP information of the current point may be transmitted up to the N^(th)sub-frame (e.g., 2^(nd) sub-frame) within an MPH frame. Then, theensemble MAP information of the next point may be transmitted startingfrom the 3^(rd) sub-frame. Finally, the service or system information ofthe current point may be transmitted from all sub-frame sections.

As described above, if the information of the next point is transmittedin advance within an MPH frame, the receiving system may repeatedlyreceive in advance important transmission parameters (e.g.,FEC-associated information, ensemble MAP information, etc.) that are tobe used in a future MPH frame. Thus, the receiving system can receivecorresponding ensembles with more stability even when diverseinterference occurs in the channel. Furthermore, since the receivingsystem can extract known data place information, the receiving systemmay estimate a signaling information region based upon the extractedknown data place information. Thereafter, the receiving system mayextract the signaling information from the estimated signalinginformation region and decode the extracted signaling information,thereby using the decoded signaling information to recover the mobileservice data.

FIG. 26 illustrates a block diagram showing the structure of thepre-processor according to another embodiment of the present invention.Herein, FIG. 26 shows an example for scattering and transmittingparticularly the mobile service data in the time section.

More specifically, the mobile service data are randomized by the datarandomizer 701 and then inputted to the RS encoder 702. The RS encoder702 receives the randomized mobile service data and performs errorcorrection encoding on the received randomized mobile service data. Forexample, the RS encoder 702 may perform error detection encoding on theerror correction encoded mobile service data. Herein, RS-encoding isapplied for the error correction encoding process, and a cyclicredundancy check (CRC) encoding is applied for the error detectionprocess. When performing the RS-encoding, parity data that are used forthe error correction are generated. And, when performing the CRCencoding, CRC data that are used for the error detection are generated.The RS encoding is one of forward error correction (FEC) methods.

The mobile service data being encoded by the RS encoder 702 for errorcorrection are inputted to the data interleaver 703. Thus, aninterleaving process scattering data along a time axis is performed. Theinterleaved mobile service data are inputted to the outer encoder 704,thereby being outer-encoded. The embodiment of the outer encoder 704 maycorrespond to the block processor. At this point, the outer encoder 704is controlled by the diversity controller 700 so as to decide the codingrate. Then, after performing 1/N-rate encoding on one bit input, therebyforming an N-bit output, the encoded mobile service data are dividedinto a plurality of output masses with respect to the correspondingdiversity degree value. The outer encoder 704 may independently performtrellis-encoding on the mobile service data of each output mass.

The mobile service data corresponding to each output mass of the outerencoder 704 are inputted to the outer interleaver 705. The outerinterleaver 705 independently performs outer interleaving on the mobileservice data corresponding to each output mass, so as to realign thedata order, thereby outputting the processed data to the diversitybuffer 706. Herein, the bit-unit interleaving and symbol-unitinterleaving are performed as embodiments of the outer interleavingprocess. The output of the outer interleaver 705 is temporarily storedin the diversity buffer 706. Then, based upon the control of thediversity controller 700, the diversity buffer 706 outputs the mobileservice data corresponding to each output mass to the symbol multiplexer707, while taking into consideration the diversity method, thetransmission unit, and the transmission cycle period.

For example, in case of time diversity transmission, each output massstored in the diversity buffer 706 is outputted to a turbo stuffer 713through the symbol multiplexer 707 at different timing points.

Meanwhile, the signaling information (or SIC (Signaling InformationChannel)), such as transmission parameter and diversity processinginformation, is randomized by the data randomizer 708, error-correctionencoded by the RS encoder 709, outer-encoded by the outer encoder 710,and interleaved by the outer interleaver 711, thereby being inputted tothe symbol multiplexer 707. More specifically, the diversity processinginformation, which corresponds to one of the SIC data required by thereceiving system for recovering the mobile service data transmitted bythe transmitting system, are additionally loaded in the SIC orinformation of a higher layer and transmitted, so that the receivingsystem can adequately recover the diversity transmission. The SIC dataincluding the diversity processing information may either be processedwith both outer-encoding and trellis-coding, just as the mobile servicedata, thereby being outputted, or be processed with only one of thecoding processes, thereby being outputted.

The symbol multiplexer 707 multiplexes the signaling information andmobile service data corresponding to each output mass in accordance witha pre-determined multiplexing rule, thereby outputting the multiplexeddata to the turbo stuffer 713.

The turbo stuffer 713 combines the main service data being inputtedthrough a transmission adaptor 712 with the output data of the symbolmultiplexer 707, thereby outputting the combined data to the exciter714. At this point, the turbo stuffer 713 may perform trellis-coding onthe main service data and the mobile service data. Herein, thetrellis-coding process may be performed prior to or after the symbolmultiplexing process. The exciter 714 inserts a field synchronizationsignal, a segment synchronization signal, and a pilot in the output ofthe turbo stuffer 713, thereby modulating the processed data by apredetermined modulation method, such as the VSB method, and outputtingthe modulated data to the receiving system. Thus, the mobile servicedata corresponding to each output mass are assigned to differenttransmission sections, so as to be processed with time diversitytransmission, as shown in FIG. 9( a).

Meanwhile, the blocks marked by dotted lines in FIG. 26 respectivelycorrespond to blocks that are additionally required for scattering themobile service data to two different frequencies and transmitting thescattered data as diversity information. More specifically, in order toscatter mobile service data to M number of different frequencies, Mnumber of dotted blocks are required. The basic functions of each ofthese blocks are identical to the functions of the blocks marked insolid lines. However, the output frequency of the dotted exciter must bedifferent from the output frequency of the solid line exciter 714.

Demodulating Unit within Receiving System

FIG. 27 illustrates an example of a demodulating unit in a receivingsystem according to the present invention. The demodulating unit of FIG.27 uses known data information, which is inserted in the mobile servicedata section and, then, transmitted by the transmitting system, so as toperform carrier synchronization recovery, frame synchronizationrecovery, and channel equalization, thereby enhancing the receivingperformance. Also the demodulating unit may turn the power on onlyduring a slot to which the data group of the designated (or desired)parade is assigned, thereby reducing power consumption of the receivingsystem.

Referring to FIG. 27, the demodulating unit includes a demodulator 802,an equalizer 803, a known sequence detector 804, a block decoder 805, aRS frame decoder 806, and a derandomizer 807. The demodulating unit mayfurther include a data deinterleaver 809, a RS decoder 810, and a dataderandomizer 811. The demodulating unit may further include a signalingdecoder 813. The receiving system also may further include a powercontroller 800 for controlling power supply of the demodulating unit.

Herein, for simplicity of the description of the present invention, theRS frame decoder 806, and the derandomizer 807 will be collectivelyreferred to as a mobile service data processing unit. And, the datadeinterleaver 809, the RS decoder 810, and the data derandomizer 811will be collectively referred to as a main service data processing unit.For example, when a receiving system is for receiving mobile servicedata only, the main service data processor may be omitted in thestructure of the receiving system.

More specifically, a frequency of a particular channel tuned by a tunerdown converts to an intermediate frequency (IF) signal. Then, thedown-converted data 801 outputs the down-converted IF signal to thedemodulator 802 and the known sequence detector 804. At this point, thedown-converted data 801 is inputted to the demodulator 802 and the knownsequence detector 804 via analog/digital converter ADC (not shown). TheADC converts pass-band analog IF signal into pass-band digital IFsignal.

The demodulator 802 performs self gain control, carrier recovery, andtiming recovery processes on the inputted pass-band digital IF signal,thereby modifying the IF signal to a base-band signal. Then, thedemodulator 802 outputs the newly created base-band signal to theequalizer 803 and the known sequence detector 804.

The equalizer 803 compensates the distortion of the channel included inthe demodulated signal and then outputs the error-compensated signal tothe block decoder 805.

At this point, the known sequence detector 804 detects the knownsequence position information inserted by the transmitting end from theinput/output data of the demodulator 802 (i.e., the data prior to thedemodulation process or the data after the demodulation process).Thereafter, the position information along with the symbol sequence ofthe known data, which are generated from the detected position, isoutputted to the demodulator 802, the equalizer 803, and the signalingdecoder 813. Also, the known sequence detector 804 outputs a set ofinformation to the block decoder 805. This set of information is used toallow the block decoder 805 of the receiving system to identify themobile service data that are processed with additional encoding from thetransmitting system and the main service data that are not processedwith additional encoding.

In addition, although the connection status is not shown in FIG. 27, theinformation detected from the known sequence detector 804 may be usedthroughout the entire receiving system and may also be used in the RSframe decoder 806.

At this point, the transmitting system may periodically insert andtransmit known data within a transmission frame, as shown in FIG. 16A.

FIG. 28 illustrates an example of known data sequence being periodicallyinserted and transmitted in-between actual data by the transmittingsystem. Referring to FIG. 28, AS represents the number of general datasymbols, and BS represents the number of known data symbols. Therefore,BS number of known data symbols are inserted and transmitted at a periodof (AS+BS) symbols. Herein, AS may correspond to mobile service data,main service data, or a combination of mobile service data and mainservice data. In order to be differentiated from the known data, datacorresponding to AS will hereinafter be referred to as general data.

Referring to FIG. 28, known data sequence having the same pattern areincluded in each known data section that is being periodically inserted.Herein, the length of the known data sequence having identical datapatterns may be either equal to or different from the length of theentire (or total) known data sequence of the corresponding known datasection (or block). If the two lengths are different from one another,the length of the entire known data sequence should be longer than thelength of the known data sequence having identical data patterns. Inthis case, the same known data sequences are included in the entireknown data sequence.

Accordingly, when the known data are regularly inserted in-between thevalid data as described above, the channel equalizer included in thedigital broadcast receiver used the inserted known data as a trainingsequence, so as to be used either for an accurate decision value or forestimating an impulse response of a channel.

Meanwhile, when the same known data are regularly inserted, the knowndata interval may be used as a guard interval in a channel equalizeraccording to the present invention. Herein, the guard interval preventsinterference that occurs between blocks due to a multiple path channel.This is because the known data of the known data section located at theend portion of the data block of the (AS+BS) symbol, shown in FIG. 28,may be considered to be copied and place before the data block.

The above-described structure is referred to as a cyclic prefix. Thisstructure provides circular convolution to an impulse response in a timedomain between a data block transmitted from the transmitting system anda channel. Accordingly, this facilitates the channel equalizer of areceiving system to perform channel equalization in a frequency domainby using a fast fourier transform (FFT) and an inverse fast fouriertransform (IFFT).

More specifically, when viewed in the frequency domain, the data blockreceived by the receiving system is expressed as a multiplication of thedata block and the channel impulse response. Therefore, when performingthe channel equalization, by multiplying the inverse of the channel inthe frequency domain, the channel equalization may be performed moreeasily.

The known data detector 804 detects the position of the known data beingperiodically inserted and transmitted as described above. At the sametime, the known data detector 804 may also estimate initial frequencyoffset during the process of detecting known data. In this case, thedemodulator 802 may estimate with more accuracy carrier frequency offsetfrom the information on the known data position (or known sequenceposition indicator) and initial frequency offset estimation value,thereby compensating the estimated carrier frequency offset.

Meanwhile, when the known data are transmitted in the same structure asthat shown in FIG. 16A, the known sequence detector 804 initiallydetects the position of the second known data region using second knowndata, which the same pattern is repeated twice, included in the secondknown data region.

At this point, since the known sequence detector 804 is well-informed ofthe data group structure, when the position of the second known dataregion is detected, the known sequence detector 804 can estimatepositions of the 1^(st) known data region and 3^(rd) to 6^(th) knowndata regions of a corresponding data group, by counting symbols orsegments based upon the second known data region position. Also, whenthe corresponding data group includes a field synchronization segment,the known sequence detector 804 can further estimate the position of thefield synchronization segment of the corresponding data group, which ispositioned chronologically before the second known data region, bycounting symbols or segments based upon the second known data regionposition. The known sequence detector 804 also may configure an ensemblemap by inputting an MPH-related information from the signalinginformation decoder 813, and output the known data position informationand field synchronization position information from the ensembleincluding the service which a user select based upon the ensemble map.

The estimated position information of the field synchronization segmentand known data regions are provided to the demodulator 802 and theequalizer 803.

Also, the known sequence detector 804 can estimate an initial frequencyoffset using the known data inserted in the second known data region(i.e., ACQ known data region).

In this case, the demodulator 802 may estimate with more accuracycarrier frequency offset from the known data position information andthe initial frequency offset estimation value, thereby compensating theestimated carrier frequency offset.

More specifically, the demodulator 802 may use the known data in orderto detect the timing error. In the example of the present invention, thetiming error may be detected by using a correlation characteristicbetween the known data and the received data in the time domain, theknown data being already known in accordance with a pre-arrangedagreement between the transmitting system and the receiving system. Thetiming error may also be detected by using the correlationcharacteristic of the two known data types being received in thefrequency domain.

The equalizer 803 may perform channel equalization by using a pluralityof methods. An example of estimating a channel impulse response (CIR) soas to perform channel equalization will be given in the description ofthe present invention.

Most particularly, an example of estimating the CIR in accordance witheach region within the data group, which is hierarchically divided andtransmitted from the transmitting system, and applying each CIRdifferently will also be described herein. Furthermore, by using theknown data, the place and contents of which is known in accordance withan agreement between the transmitting system and the receiving system,and/or the field synchronization data, so as to estimate the CIR, thepresent invention may be able to perform channel equalization with morestability.

Herein, the data group that is inputted for the equalization process isdivided into regions A to D, as shown in FIG. 16A. More specifically, inthe example of the present invention, each region A, B, C, and D arefurther divided into MPH blocks B4 to B7, MPH blocks B3 and B8, MPHblocks B2 and B9, MPH blocks B1 and B10, respectively.

More specifically, a data group can be assigned and transmitted amaximum the number of 4 in a VSB frame in the transmitting system. Inthis case, all data group do not include field synchronization data. Inthe present invention, the data group including the fieldsynchronization data performs channel-equalization using the fieldsynchronization data and known data. And the data group not includingthe field synchronization data performs channel-equalization using theknown data. For example, the data of the MPH block B3 including thefield synchronization data performs channel-equalization using the CIRcalculated from the field synchronization data area and the CIRcalculated from the first known data area. Also, the data of the MPHblocks B1 and B2 performs channel-equalization using the CIR calculatedfrom the field synchronization data area and the CIR calculated from thefirst known data area. Meanwhile, the data of the MPH blocks B4 to B6not including the field synchronization data performschannel-equalization using CIRS calculated from the first known dataarea and the third known data area.

As described above, the present invention uses the CIR estimated fromthe field synchronization data and the known data sequences in order toperform channel equalization on data within the data group. At thispoint, each of the estimated CIRs may be directly used in accordancewith the characteristics of each region within the data group.Alternatively, a plurality of the estimated CIRs may also be eitherinterpolated or extrapolated so as to create a new CIR, which is thenused for the channel equalization process.

Herein, when a value F(Q) of a function F(x) at a particular point Q anda value F(S) of the function F(x) at another particular point S areknown, interpolation refers to estimating a function value of a pointwithin the section between points Q and S. Linear interpolationcorresponds to the simplest form among a wide range of interpolationoperations. The linear interpolation described herein is merelyexemplary among a wide range of possible interpolation methods. And,therefore, the present invention is not limited only to the examples setforth herein.

Alternatively, when a value F(Q) of a function F(x) at a particularpoint Q and a value F(S) of the function F(x) at another particularpoint S are known, extrapolation refers to estimating a function valueof a point outside of the section between points Q and S. Linearextrapolation is the simplest form among a wide range of extrapolationoperations. Similarly, the linear extrapolation described herein ismerely exemplary among a wide range of possible extrapolation methods.And, therefore, the present invention is not limited only to theexamples set forth herein.

Power On/Off Control

The data demodulated in the demodulator 802 or the data equalized in thechannel equalizer 803 is inputted to the signaling information decoder813. The known data information detected in the known sequence detector804 is inputted to the signaling information decoder 813.

The signaling information decoder 813 extracts and decodes signalinginformation from the inputted data, the decoded signaling informationprovides to blocks requiring the signaling information. For example, thediversity processing information may output to the block decoder 805,and the RS frame-associated information may output to the RS framedecoder 806. The MPH frame-associated information may output to theknown sequence detector 804 and the power controller 800.

Herein, the MPH frame-associated information may include sub-frame countinformation, slot count information, ensemble_id information, SGNinformation, NoG information, ETP information and so on.

More specifically, the signaling information between first known dataarea and second known data area can know by using known data informationbeing outputted in the known sequence detector 804. Therefore, thesignaling information decoder 813 may extract and decode signalinginformation from the data being outputted in the demodulator 802 or thechannel equalizer 803.

The power controller 800 may configure the ensemble map by inputting theMPH frame-associated information from the signaling information decoder813, and controls power of the tuner and the demodulating unit dependingupon the ensemble map.

According to the embodiment of the present invention, the powercontroller 800 turns the power on only during a slot to which a datagroup of the ensemble including user-selected mobile service isassigned. The power controller 800 then turns the power off during theremaining slots.

For example, it is assumed that data groups of a 1^(st) ensemble withNOG=3, a 2^(nd) ensemble with NOG=4 are assigned to one MPH frame, asshown in FIG. 22( a). It is also assumed that the user has selected amobile service included in the 1^(st) ensemble using the keypad providedon the remote controller or terminal. In this case, the power controller800 turns the power on only during slots that data groups of the 1^(st)ensemble is assigned, as shown in FIG. 2( b), and turns the power offduring the remaining slots, thereby reducing power consumption.

Block Decoder

Meanwhile, if the data being inputted to the block decoder 805, afterbeing channel-equalized by the equalizer 803, correspond to the datahaving both block encoding and trellis encoding performed thereon (i.e.,the data within the RS frame, the signaling information data, etc.) bythe transmitting system, trellis decoding and block decoding processesare performed on the inputted data as inverse processes of thetransmitting system. Alternatively, if the data being inputted to theblock decoder 805 correspond to the data having only trellis encodingperformed thereon (i.e., the main service data), and not the blockencoding, only the trellis decoding process is performed on the inputteddata as the inverse process of the transmitting system.

The trellis decoded and block decoded data by the block decoder 805 arethen outputted to the RS frame decoder 806. More specifically, the blockdecoder 805 removes the known data, data used for trellisinitialization, and signaling information data, MPEG header, which havebeen inserted in the data group, and the RS parity data, which have beenadded by the RS encoder/non-systematic RS encoder or non-systematic RSencoder of the transmitting system. Then, the block decoder 805 outputsthe processed data to the RS frame decoder 806. Herein, the removal ofthe data may be performed before the block decoding process, or may beperformed during or after the block decoding process.

Meanwhile, the data trellis-decoded by the block decoder 805 areoutputted to the data deinterleaver 809. At this point, the data beingtrellis-decoded by the block decoder 805 and outputted to the datadeinterleaver 809 may not only include the main service data but mayalso include the data within the RS frame and the signaling information.Furthermore, the RS parity data that are added by the transmittingsystem after the pre-processor 230 may also be included in the databeing outputted to the data deinterleaver 809.

According to another embodiment of the present invention, data that arenot processed with block decoding and only processed with trellisencoding by the transmitting system may directly bypass the blockdecoder 805 so as to be outputted to the data deinterleaver 809. In thiscase, a trellis decoder should be provided before the data deinterleaver809. More specifically, if the inputted data correspond to the datahaving only trellis encoding performed thereon and not block encoding,the block decoder 805 performs Viterbi (or trellis) decoding on theinputted data so as to output a hard decision value or to perform ahard-decision on a soft decision value, thereby outputting the result.

Meanwhile, if the inputted data correspond to the data having both blockencoding process and trellis encoding process performed thereon, theblock decoder 805 outputs a soft decision value with respect to theinputted data.

In other words, if the inputted data correspond to data being processedwith block encoding by the block processor 302 and being processed withtrellis encoding by the trellis encoding module 606 in the transmittingsystem, the block decoder 805 performs a decoding process and a trellisdecoding process on the inputted data as inverse processes of thetransmitting system. At this point, the RS frame encoder of thepre-processor included in the transmitting system may be viewed as anouter (or external) encoder. And, the trellis encoder may be viewed asan inner (or internal) encoder. When decoding such concatenated codes,in order to allow the block decoder 805 to maximize its performance ofdecoding externally encoded data, the decoder of the internal codeshould output a soft decision value.

FIG. 29 illustrates a detailed block diagram of the block decoder 805according to an embodiment of the present invention. Referring to FIG.29, the block decoder 805 includes an input buffer 901, a trellisdecoding unit (or 12-way trellis coded modulation (TCM) decoder or innerdecoder) 902, a feedback deformatter 903, a symbol deinterleaver 904, anouter symbol mapper 905, a symbol decoder 906, an inner symbol mapper907, a symbol interleaver 908, a feedback formatter 909, and an outputbuffer 910. Herein, just as in the transmitting system, the trellisdecoding unit 902 may be viewed as an inner (or internal) decoder. And,the symbol decoder 906 may be viewed as an outer (or external) decoder.

Also, if the transmitting system divided the mobile service data into aplurality of output masses and performed diversity transmission,processing of the corresponding data should be performed by the inputbuffer, the trellis encoder, the feedback deformatter, the symboldeinterleaver, and the packet formatter, the number of which correspondsto the number of output masses. When the diversity degree is ‘2’, thedotted-lined blocks of FIG. 29 correspond to the block decoder. Morespecifically, the block decoder of FIG. 29 including the dotted-linedblocks may decode mobile service data having the diversity degree of‘2’. In case of the frequency diversity transmission, demodulators andequalizers are further required, the numbers of demodulators andequalizers corresponding to the diversity degree.

At this point, the diversity processing information on the diversitymethod and structure, which is transmitted from the transmitting system,is included in the signaling information or channel information of anupper layer and transmitted. Therefore, the data of each output mass maybe inputted to the corresponding input buffer. More specifically, amongthe data being inputted to each input buffer 901 and 901-1, the mobileservice data correspond to symbols belonging to each output mass mob Aand mob B, which are transmitted as shown in FIG. 9( a), FIG. 9( b), andFIG. 9( c). For example, the mobile service data symbol of the outputmass mob A is inputted to the input buffer 901, and the mobile servicedata symbol of the output mass mob B is inputted to the input buffer901-1, and vice versa.

Since each of the output masses is encoded by an independent symbolinterleaver, as shown in FIG. 10 to FIG. 12B, the block decoder alsorequires an independent symbol interleaver and an independent symboldeinterleaver.

Also, since the block processor of the transmitting system has dividedand outputted the 1/N-rate encoded mobile service data to 2 outputmasses, an outer symbol mapper 905 groups the soft-decision value of theoutput symbol outputted from the two symbol deinterleavers 904 and904-1, so as to configure one soft-decision value and output the onesoft-decision value to the symbol decoder 906. Additionally, an innersymbol mapper 907 breaks-down (or divides) one soft-decision valueoutputted from the symbol decoder 906 into two soft-decision values,which are then respectively outputted to each symbol interleaver 908 and908-1. In order to do so, the input buffers 901 and 901-1, the outersymbol mappers 905 and 905-1, and the inner symbol mappers 907 and 907-1may receive the decoded diversity processing information from thesignaling information decoder 813.

When excluding the portion marked in dotted lines of FIG. 29, theabove-described diversity-specific block decoder may also be operated asa general block decoder. For example, even in a situation when theoutput mass mob A cannot be received due to the initial turning-on ofthe receiver or a change in the frequency channel, the block decodingfunction may be performed by using only the other output mass mob B.Therefore, the above-described diversity-specific block decoder isadvantageous in that, even when any one of the output masses mob A ormob B is not completely received, data recovery can be performed byusing just one output mass.

Hereinafter, the solid-lined blocks included in the block decoder ofFIG. 29 will be described in detail. Since the functions and operationsof the dotted-lined blocks are similar to those of the solid-linedblocks, detailed description of the same will be omitted for simplicity.More specifically, among the symbol values being channel-equalized andoutputted from the equalizer 803, the input buffer 901 temporarilystores the mobile service data symbol (including RS parity data symbolsadded when performing RS-frame encoding and CRC data symbols) values ofthe corresponding output mass, which is block-encoded anddiversity-transmitted. Then, the input buffer 901 repeatedly outputs thestored symbol values for M number of times to the trellis decoder 902 ina turbo decoding length (TDL) size for turbo decoding. The turbodecoding length (TDL) size may also be referred to as a turbo block.Herein, a TDL should include at least one MPH block size. The value of Mcorresponds to a number of repetitions of the pre-decided turbo decodingprocess.

Also, among the values of symbols being channel-equalized and outputtedfrom the equalizer 803, the input symbol values corresponding to asection having no mobile service data symbols (including RS parity datasymbols during RS frame encoding and CRC data symbols) included therein,bypass the input buffer 901 without being stored. More specifically,since trellis-encoding is performed on input symbol values of a sectionwherein block-encoding has not been performed, the input buffer 901inputs the inputted symbol values of the corresponding section directlyto the trellis decoding module 902 without performing any storage,repetition, and output processes.

The storage, repetition, and output processes of the input buffer 901are controlled by the feedback controller (not shown). Herein, thefeedback controller refers to diversity processing information, which isoutputted from the signaling information decoder 813, in order tocontrol the storage and output processes of the input buffer 901.

The trellis decoding unit 902 includes a 12-way TCM decoder. Herein, thetrellis decoding unit 902 performs 12-way trellis decoding as inverseprocesses of the 12-way trellis encoder.

More specifically, the trellis decoding unit 902 receives a number ofoutput symbols of the input buffer 901 and soft-decision values of thefeedback formatter 909 equivalent to each TDL, so as to perform the TCMdecoding process.

At this point, based upon the control of the feedback controller, thesoft-decision values outputted from the feedback formatter 909 arematched with a number of mobile service data symbol places so as to bein a one-to-one (1:1) correspondence. Herein, the number of mobileservice data symbol places is equivalent to the TDL being outputted fromthe input buffer 901.

More specifically, the mobile service data being outputted from theinput buffer 901 are matched with the turbo decoded data being inputted,so that each respective data place can correspond with one another.Thereafter, the matched data are outputted to the trellis decoding unit902. For example, if the turbo decoded data correspond to the thirdsymbol within the turbo block, the corresponding symbol (or data) ismatched with the third symbol included in the turbo block, which isoutputted from the input buffer 901. Subsequently, the matched symbol(or data) is outputted to the trellis decoding unit 902.

In order to do so, while the regressive turbo decoding is in process,the feedback controller controls the input buffer 901 so that the inputbuffer 901 stores the corresponding turbo block data. Also, by delayingdata (or symbols), the soft decision value (e.g., LLR) of the symboloutputted from the symbol interleaver 908 and the symbol of the inputbuffer 901 corresponding to the same place (or position) within theblock of the output symbol are matched with one another to be in aone-to-one correspondence. Thereafter, the matched symbols arecontrolled so that they can be inputted to the TCM decoder through therespective path. This process is repeated for a predetermined number ofturbo decoding cycle periods. Then, the data of the next turbo block areoutputted from the input buffer 901, thereby repeating the turbodecoding process.

The output of the trellis decoding unit 902 signifies a degree ofreliability of the transmission bits configuring each symbol. Forexample, in the transmitting system, since the input data of the trellisencoding module 606 correspond to two bits as one symbol, a loglikelihood ratio (LLR) between the likelihood of a bit having the valueof ‘1’ and the likelihood of the bit having the value of ‘0’ may berespectively outputted (in bit units) to the upper bit and the lowerbit. Herein, the log likelihood ratio corresponds to a log value for theratio between the likelihood of a bit having the value of ‘1’ and thelikelihood of the bit having the value of ‘0’. Alternatively, a LLR forthe likelihood of 2 bits (i.e., one symbol) being equal to “00”, “01”,“10”, and “11” may be respectively outputted (in symbol units) to all 4combinations of bits (i.e., 00, 01, 10, 11). Consequently, this becomesthe soft decision value that indicates the degree of reliability of thetransmission bits configuring each symbol. A maximum a posterioriprobability (MAP) or a soft-out Viterbi algorithm (SOVA) may be used asa decoding algorithm of each TCM decoder within the trellis decodingunit 902.

The output of the trellis decoding unit 902 is inputted to the feedbackdeformatter 903.

If the receiving system includes the main service data processor, theoutput of the trellis decoding unit 902 also is outputted to the datadeinterleaver 809. At this time, the trellis decoding unit 902 performsa hard-decision process of the soft decision value that is trellisdecoded and outputted from the trellis decoding unit 902, and groups 4symbols into byte units, which are then outputted to the datadeinterleaver 809. The data deinterleaver 809 receives mobile servicedata, known data, signaling information data, RS parity data, MPEGheader, and so on as well as main service data.

Among the soft decision values of TDL size of the trellis decoding unit902, the feedback deformatter 903 receives the soft decision values ofBK size of corresponding to the mobile service data symbols (whereinsymbols corresponding to signaling information, RS parity data symbolsthat are added during the encoding of the RS frame, and CRC data symbolsare included). More specifically, the feedback deformatter 903 does notreceive the soft decision values of the main service data, known data,signaling information data, RS parity data, and MPEG header and so on.

The feedback deformatter 903 changes the processing order of the softdecision values corresponding to the mobile service data symbols. Thisis an inverse process of an initial change in the processing order ofthe mobile service data symbols, which are generated during anintermediate step, wherein the output symbols outputted from the blockprocessor 303 of the transmitting system are being inputted to thetrellis encoding module 606 (e.g., when the symbols pass through thegroup formatter, the data deinterleaver, the packet formatter, and thedata interleaver). Thereafter, the feedback deformatter 903 performsreordering of the process order of soft decision values corresponding tothe mobile service data symbols and, then, outputs the processed mobileservice data symbols to the symbol deinterleaver 904.

This is because a plurality of blocks exist between the block processor303 and the trellis encoding module 606, and because, due to theseblocks, the order of the mobile service data symbols being outputtedfrom the block processor 303 and the order of the mobile service datasymbols being inputted to the trellis encoding module 606 are notidentical to one another. Therefore, the feedback deformatter 903reorders (or rearranges) the order of the mobile service data symbols,so that the order of the mobile service data symbols being inputted tothe symbol deinterleaver 904 matches the order of the mobile servicedata symbols outputted from the block processor 303 of the transmittingsystem. The reordering process may be embodied as one of software,middleware, and hardware.

FIG. 30 illustrates a detailed block diagram of the feedback deformatter903 according to an embodiment of the present invention. Herein, thefeedback deformatter 903 includes a data deinterleaver 1001, a packetdeformatter 1002, a data interleaver 1003, and a group deformatter 1004.

Referring to FIG. 30, the soft decision value of the mobile service datasymbol, which is inputted from the trellis decoding unit 902, isoutputted to the data deinterleaver 1001 of the feedback deformatter 903without modification. However, data place holders (or null data) areinserted in data places (e.g., main service data places, known dataplaces, signaling information places, RS parity data places, and MPEGheader places), thereby being outputted to the data deinterleaver 1001of the feedback deformatter 903.

The data deinterleaver 1001 performs an inverse process of the datainterleaver 603 included in the transmitting system. More specifically,the data deinterleaver 1001 deinterleaves the inputted data and outputsthe deinterleaved data to the packet deformatter 1002.

The packet deformatter 1002 performs an inverse process of the packetformatter 308. More specifically, among the data that are deinterleavedand outputted from the data deinterleaver 1001, the packet deformatter1002 removes the place holder corresponding to the MPEG header, whichhad been inserted to the packet formatter 308. The output of the packetdeformatter 1002 is inputted to the data interleaver 1003, and the datainterleaver 1003 interleaves the data being inputted, as an inverseprocess of the data deinterleaver included in the transmitting system.Accordingly, data having a data structure as shown in FIG. 16A, areoutputted to the group deformatter 1004.

The group deformatter 1004 performs an inverse process of the groupformatter included in the transmitting system. More specifically, thegroup formatter 1004 removes the place holders corresponding to the mainservice data, known data, signaling information data, and RS paritydata. Then, the group formatter 1004 outputs only the reordered (orrearranged) mobile service data symbols to the symbol deinterleaver 904.According to another embodiment of the present invention, when thefeedback deformatter 903 is embodied using a memory map, the process ofinserting and removing place holder from data position which is notinputted may be omitted.

The symbol deinterleaver 904 performs deinterleaving on the mobileservice data symbols having their processing orders changed andoutputted from the feedback deformatter 903, as an inverse process ofthe symbol interleaving process of the symbol interleaver included inthe transmitting system. The size of the block used by the symboldeinterleaver 904 during the deinterleaving process is identical tointerleaving size of an actual symbol (i.e., BK) of the symbolinterleaver, which is included in the transmitting system. This isbecause the turbo decoding process is performed between the trellisdecoding unit 902 and the symbol decoder 906. Both the input and outputof the symbol deinterleaver 904 correspond to soft decision values, andthe deinterleaved soft decision values are outputted to the outer symbolmapper 905.

The operations of the outer symbol mapper 905 may vary depending uponthe structure and coding rate of the symbol encoding unit 402 includedin the transmitting system. For example, when data are ½-rate encoded bythe symbol encoding unit 402 and then transmitted, the outer symbolmapper 905 directly outputs the input data without modification. Inanother example, when data are ¼-rate encoded by the symbol encodingunit 402 and then transmitted, the outer symbol mapper 905 converts theinput data so that it can match the input data format of the symboldecoder 906.

At this point, when it is assumed that the block processor of thetransmitting system divides the ¼-rate encoded mobile service data totwo ½-rate output masses and diversity-outputs the divided outputmasses, the outer symbol mapper 906 configures one symbol soft decisionvalue by combining the symbol soft decision values of the two symbolinterleavers 904 and 904-1, and then outputs the combined symbol softdecision value to the symbol decoder 906. For this, the outer symbolmapper 905 may be inputted diversity processing information from thesignaling information decoder 813.

The symbol decoder 906 (i.e., the outer decoder) receives the dataoutputted from the outer symbol mapper 905 and performs symbol decodingas an inverse process of the symbol encoding unit 402 included in thetransmitting system. At this point, two different soft decision valuesare outputted from the symbol decoder 906. One of the outputted softdecision values corresponds to a soft decision value matching the outputsymbol of the symbol encoding unit 402 (hereinafter referred to as a“first decision value”). The other one of the outputted soft decisionvalues corresponds to a soft decision value matching the input bit ofthe symbol encoding unit 402 (hereinafter referred to as a “seconddecision value”).

More specifically, the first decision value represents a degree ofreliability the output symbol (i.e., 2 bits) of the symbol encoding unit402. Herein, the first soft decision value may output (in bit units) aLLR between the likelihood of 1 bit being equal to ‘1’ and thelikelihood of 1 bit being equal to ‘0’ with respect to each of the upperbit and lower bit, which configures a symbol. Alternatively, the firstsoft decision value may also output (in symbol units) a LLR for thelikelihood of 2 bits being equal to “00”, “01”, “10”, and “11” withrespect to all possible combinations. The first soft decision value isfed-back to the trellis decoding unit 902 through the inner symbolmapper 907, the symbol interleaver 908, and the feedback formatter 909.On the other hand, the second soft decision value indicates a degree ofreliability the input bit of the symbol encoding unit 402 included inthe transmitting system. Herein, the second soft decision value isrepresented as the LLR between the likelihood of 1 bit being equal to‘1’ and the likelihood of 1 bit being equal to ‘0’. Thereafter, thesecond soft decision value is outputted to the outer buffer 910. In thiscase, a maximum a posteriori probability (MAP) or a soft-out Viterbialgorithm (SOVA) may be used as the decoding algorithm of the symboldecoder 906.

The first soft-decision value being outputted from the symbol decoder906 is inputted to the inner symbol mapper 907. The inner symbol mapper907 converts the received first soft-decision value to match the inputformat of the trellis decoder 902, thereby outputting the convertedfirst soft-decision value to the symbol interleaver 908. The operationof the inner symbol mapper 907 may also vary depending upon thestructure and coding rate of the symbol encoding unit 402 included inthe transmitting system. At this point, when it is assumed that theblock processor of the transmitting system divides the ¼-rate encodedmobile service data to two ½-rate output masses and diversity-outputsthe divided output masses, the inner symbol mapper 907 divides the onefirst soft-decision value outputted from the symbol decoder 906 into twosoft-decision values and respectively outputs the divided soft-decisionvalues to the symbol interleaver 908 and 908-1.

The symbol interleaver 908 performs symbol interleaving, as shown inFIG. 15, on the first soft decision value that is outputted from theinner symbol mapper 907. Then, the symbol interleaver 908 outputs thesymbol-interleaved first soft decision value to the feedback formatter909. Herein, the output of the symbol interleaver 908 also correspondsto a soft decision value.

With respect to the changed processing order of the soft decision valuescorresponding to the symbols that are generated during an intermediatestep, wherein the output symbols outputted from the block processor 303of the transmitting system are being inputted to the trellis encodingmodule (e.g., when the symbols pass through the group formatter, thedata deinterleaver, the packet formatter, the RS encoder, and the datainterleaver), the feedback formatter 909 alters (or changes) the orderof the output values outputted from the symbol interleaver 908.Subsequently, the feedback formatter 908 outputs values to the trellisdecoding unit 902 in the changed order.

The soft decision values outputted from the symbol interleaver 908 arematched with the positions of mobile service data symbols each havingthe size of TDL, which are outputted from the input buffer 901, so as tobe in a one-to-one correspondence. Thereafter, the soft decision valuesmatched with the respective symbol position are inputted to the trellisdecoding unit 902. At this point, since the main service data symbols orthe RS parity data symbols and known data symbols of the main servicedata do not correspond to the mobile service data symbols, the feedbackformatter 909 inserts null data in the corresponding positions, therebyoutputting the processed data to the trellis decoding unit 902.Additionally, each time the symbols having the size of TDL are turbodecoded, no value is fed-back by the symbol interleaver 908 startingfrom the beginning of the first decoding process. Therefore, thefeedback formatter 909 is controlled by the feedback controller, therebyinserting null data into all symbol positions including a mobile servicedata symbol. Then, the processed data are outputted to the trellisdecoding unit 902.

The output buffer 910 receives the second soft decision value from thesymbol decoder 906 based upon the control of the feedback controller.Then, the output buffer 910 temporarily stores the received second softdecision value. Thereafter, the output buffer 910 outputs the secondsoft decision value to the RS frame decoder 806. For example, the outputbuffer 910 overwrites the second soft decision value of the symboldecoder 906 until the turbo decoding process is performed for M numberof times. Then, once all M number of turbo decoding processes isperformed for a single TDL, the corresponding second soft decision valueis outputted to the RS frame decoder 806.

The feedback controller controls the number of turbo decoding and turbodecoding repetition processes of the overall block decoder, shown inFIG. 29.

At this point, the number of regressive turbo decoding rounds betweenthe trellis decoding unit 902 and the symbol decoder 906 may be definedwhile taking into account hardware complexity and error correctionperformance. Accordingly, if the number of rounds increases, the errorcorrection performance may be enhanced. However, this may lead to adisadvantageous of the hardware becoming more complicated (or complex).

Meanwhile, the data deinterleaver 809, the RS decoder 810, and the dataderandomizer 811 correspond to blocks required for receiving the mainservice data. Therefore, the above-mentioned blocks may not be necessary(or required) in the structure of a receiving system for receivingmobile service data only. The data deinterleaver 809 performs an inverseprocess of the data interleaver included in the transmitting system. Inother words, the data deinterleaver 809 deinterleaves the main servicedata outputted from the block decoder 805 and outputs the deinterleavedmain service data to the RS decoder 810. The data being inputted to thedata deinterleaver 809 include main service data, as well as mobileservice data, known data, RS parity data, and an MPEG header.

The RS decoder 810 performs a systematic RS decoding process on thedeinterleaved data and outputs the processed data to the dataderandomizer 811.

The data derandomizer 811 receives the output of the RS decoder 810 andgenerates a pseudo random data byte identical to that of the randomizerincluded in the transmitting system. Thereafter, the data derandomizer811 performs a bitwise exclusive OR (XOR) operation on the generatedpseudo random data byte, thereby inserting the MPEG synchronizationbytes to the beginning of each packet so as to output the data in188-byte main service data packet units.

FIG. 31 illustrates the demodulating unit within the receiving systemaccording to another embodiment of the present invention. Thedemodulating unit of FIG. 31 includes demodulator 2002, an equalizer2003, a known sequence detector (or a known data detector) 2004, a turbodecoder 2005, a time interleaver 2006, a RS decoder 2007, and aderandomizer 2008. The demodulating unit may further include an RSdecoder 2009 and a derandomizer 2010. The demodulating unit may furtherinclude a TCM decoder 2011, a time interleaver 2012, RS decoder 2013,and derandomizer 2014. More specifically, when a tuner tunes to afrequency of a specific channel having main service data and mobileservice data multiplexed therein. Thereafter, the tuned frequency of thespecific physical channel is down-converted to an intermediate frequency(IF) signal, thereby being inputted to the demodulator 2002. Thedemodulator 2002 performs self-gain control, carrier recovery, andtiming recovery processes on the inputted IF signal, thereby modifyingthe inputted IF signal to a baseband signal. Then, the demodulator 2002outputs the baseband signal to the equalizer 2003.

The known sequence detector 2004 detects the known sequence placeinserted by the transmitting system from the input/output data of thedemodulator 2002 (i.e., the data prior to the demodulation process orthe data after the demodulation process). Thereafter, the known sequencedetector 2004 outputs the place information along with the symbolsequence of the known data, which are generated from the detected place,to the demodulator 2002 and the equalizer 2003. Also, the known sequencedetector 2004 may detect MPH-associated information from the output ofthe demodulator 2002, thereby configuring tan ensemble map. Then, theknown sequence detector 2004 refers to the ensemble map, so as to outputknown data place information and field synchronization place informationin the ensemble including a user-selected service. The MPH-associatedinformation may include sub-frame count information, slot countinformation, ensemble_id information, SGN information, NOG information,ETP information, and so on.

The known sequence detector further includes a power controller (notshown) and may refer to the ensemble map so as to control the power ofthe tuner and the demodulating unit. For example, the power controllerturns the power on, so as to receive data, only during a section havinga data group of an ensemble including user-requested mobile serviceallocated (or assigned) thereto. Alternatively, the power controllerturns the power off during the remaining sections, thereby reducingexcessive power consumption. Furthermore, the known sequence detector2004 outputs information enabling the turbo decoder 2005 and the TCMdecoder 2011 to identify the mobile service data that have beenadditionally encoded by the transmitting system, and the main servicedata that have not been processed with additional encoding. The knownsequence detector 2004 outputs such identification information to theturbo decoder 2005 and the TCM decoder 2011.

The demodulator 2002 uses the known data symbol sequence during thetiming and/or carrier recovery, thereby enhancing the demodulatingperformance. Similarly, the equalizer 2003 uses the known data so as toenhance the equalizing performance. For example, a channel impulseresponse (CIR) may be estimated, so as to perform channel equalization.Then, in accordance with a predetermined method, the equalizer 2003compensates the distortion on the channel, the distortion being includedin the demodulated signal, thereby outputting the distortion-compensateddata to the turbo decoder 2005 and the TCM decoder 2011.

Among the inputted data, the turbo decoder 2005 performs turbo-decodingonly on the mobile service data and the SIC data. Also, according to anembodiment of the present invention, the block decoder of FIG. 27 may beapplied as the turbo decoder 2005. The SIC data corresponds to signalinginformation, such as a transmission parameter. If the mobile servicedata are diversity-transmitted, the signaling information including thediversity processing information should be decoded before being inputtedto the turbo decoder 2005. Furthermore, the decoded diversity processinginformation is provided to the turbo decoder 2005. Accordingly, theturbo decoder 2005 refers to the diversity processing information, so asto turbo-decode the mobile service data back to the initial state priorto dispersion, the mobile service data being dispersed and transmittedto time sections and/or frequency sections.

At this point, the turbo-decoded SIC data are outputted to the RSdecoder 2009, and the turbo-decoded mobile service data are outputted tothe time deinterleaver 2006. The RS decoder 2009 corrects the error thathas occurred in the turbo-decoded SIC data and, then, outputs theerror-corrected SIC data to the derandomizer 2010. Thereafter, thederandomizer 2010 performs derandomizing on the error-corrected SICdata. According to an embodiment of the present invention, the RSdecoder 2009 RS-decodes the turbo-decoded SIC data so as to performerror correction. At this point, at least one of the parity data and theCRC data may be used for the error correction process.

The time deinterleaver 2006 performs time-deinterleaving on theturbo-decoded mobile service data, as an inverse process of thetransmitting system. Thereafter, the time deinterleaver 2006 recoversthe data scattered along the time axis back to the initial state,thereby outputting the recovered data to the RS decoder 2007. Accordingto an embodiment of the present invention, the RS decoder 2007RS-decodes the deinterleaved mobile service data, so as to perform theerror correction process.

Among the inputted data, the TCM decoder 2011 performs TCM decoding onthe main service data, thereby outputting the processed main servicedata to the time deinterleaver 2012. The time deinterleaver 2012performs time-deinterleaving on the TCM-decoded main service data as aninverse process of the transmitting system, thereby outputting theprocessed main service data to the RS decoder 2013. The RS decoder 2013corrects the error that has occurred in main service data and, then,outputs the error-corrected main service data to the derandomizer 2014.According to an embodiment of the present invention, the RS decoder 2013RS-decodes the deinterleaved main service data so as to perform errorcorrection. The derandomizer 2014 then derandomizes the error-correctedmain service data.

FIG. 32 illustrates the demodulating unit within the receiving systemaccording to another embodiment of the present invention.

The demodulating unit of FIG. 32 includes demodulator 3002, an equalizer3003, a known sequence detector (or a known data detector) 3004, ademultiplexer 3005, a turbo decoder 3006, a time interleaver 3007, a RSdecoder 3008, and a derandomizer 3009. The demodulating unit may furtherinclude an RS decoder 3010 and a derandomizer 3011. The demodulatingunit may further include a TCM decoder 3012, a time interleaver 3013, anRS decoder 3014, and derandomizer 3015.

More specifically, when a tuner tunes to a frequency of a specificchannel having main service data and mobile service data multiplexedtherein. Thereafter, the tuned frequency of the specific physicalchannel is down-converted to an intermediate frequency (IF) signal,thereby being inputted to the demodulator 3002. The demodulator 3002performs self-gain control, carrier recovery, and timing recoveryprocesses on the inputted IF signal, thereby modifying the inputted IFsignal to a baseband signal. Then, the demodulator 3002 outputs thebaseband signal to the equalizer 3003.

The known sequence detector 3004 detects the known sequence placeinserted by the transmitting system from the input/output data of thedemodulator 3002 (i.e., the data prior to the demodulation process orthe data after the demodulation process). Thereafter, the known sequencedetector 3004 outputs the place information along with the symbolsequence of the known data, which are generated from the detected place,to the demodulator 3002 and the equalizer 3003. Also, the known sequencedetector 3004 may detect MPH-associated information from the output ofthe demodulator 3002, thereby configuring an ensemble map. Then, theknown sequence detector 3004 refers to the ensemble map, so as to outputknown data place information and field synchronization place informationin the ensemble including a user-selected service. The MPH-associatedinformation may include sub-frame count information, slot countinformation, ensemble_id information, SGN information, NOG information,ETP information, and so on.

The demodulating unit further includes a power controller (not shown)and may refer to the ensemble map so as to control the power of thetuner and the demodulating unit. For example, the power controller turnsthe power on, so as to receive data, only during a section having a datagroup of an ensemble including user-requested mobile service allocated(or assigned) thereto. Alternatively, the power controller turns thepower off during the remaining sections, thereby reducing excessivepower consumption.

The demodulator 3002 uses the known data symbol sequence during thetiming and/or carrier recovery, thereby enhancing the demodulatingperformance. Similarly, the equalizer 3003 uses the known data so as toenhance the equalizing performance. For example, a channel impulseresponse (CIR) may be estimated, so as to perform channel equalization.Then, in accordance with a predetermined method, the equalizer 3003compensates the distortion on the channel, the distortion being includedin the demodulated signal, thereby outputting the distortion-compensateddata to the demultiplexer 3005.

The demultiplexer 3005 may divide mobile service data and main servicedata from the equalized data according to a turbo data settinginformation. The mobile service data (including SIC data) divided by thedemultiplexer 3005 outputs to the turbo decoder 3006. Alternatively, themain service data divided by the demultiplexer 3005 outputs to the TCMdecoder 3012. Herein, it is assumed that the SIC data corresponds tosignaling information such as transmission parameter, and is transmittedafter turbo-coding as the mobile service data by the transmittingsystem.

The turbo decoder 3006 performs turbo-decoding on the mobile servicedata and the SIC data outputted from the demultiplexer 3005. Also,according to an embodiment of the present invention, the block decoderof FIG. 27 may be applied as the turbo decoder 3006. If the mobileservice data are diversity-transmitted, the signaling informationincluding the diversity processing information should be decoded beforebeing inputted to the turbo decoder 3006. Furthermore, the decodeddiversity processing information is provided to the turbo decoder 3006.Accordingly, the turbo decoder 3006 refers to the diversity processinginformation, so as to turbo-decode the mobile service data back to theinitial state prior to dispersion, the mobile service data beingdispersed and transmitted to time sections and/or frequency sections.

At this point, the turbo-decoded SIC data are outputted to the RSdecoder 3010, and the turbo-decoded mobile service data are outputted tothe time deinterleaver 3007.

The RS decoder 3010 corrects the error that has occurred in theturbo-decoded SIC data and, then, outputs the error-corrected SIC datato the derandomizer 3011. Thereafter, the derandomizer 3011 performsderandomizing on the error-corrected SIC data. According to anembodiment of the present invention, the RS decoder 3010 RS-decodes theturbo-decoded SIC data so as to perform error correction. At this point,at least one of the parity data and the CRC data may be used for theerror correction process.

The time deinterleaver 3007 performs time-deinterleaving on theturbo-decoded mobile service data, as an inverse process of thetransmitting system. Thereafter, the time deinterleaver 3007 recoversthe data scattered along the time axis back to the initial state,thereby outputting the recovered data to the RS decoder 3008. Accordingto an embodiment of the present invention, the RS decoder 3008RS-decodes the deinterleaved mobile service data, so as to perform theerror correction process.

The TCM decoder 3012 performs TCM decoding on the main service dataoutputted from the demultiplexer 3005, thereby outputting theTCM-decoded main service data to the time deinterleaver 3013. The timedeinterleaver 3013 performs time-deinterleaving on the TCM-decoded mainservice data as an inverse process of the transmitting system, therebyoutputting the processed main service data to the RS decoder 3014. TheRS decoder 3014 corrects the error that has occurred in main servicedata and, then, outputs the error-corrected main service data to thederandomizer 3015. According to an embodiment of the present invention,the RS decoder 3014 RS-decodes the deinterleaved main service data so asto perform error correction. The derandomizer 3015 then derandomizes theerror-corrected main service data.

FIG. 33 illustrates the demodulating unit within the receiving systemaccording to another embodiment of the present invention.

The demodulating unit of FIG. 33 includes demodulator 4002, an equalizer4003, a known sequence detector (or a known data detector) 4004, a turbodecoder 4005, a time interleaver 4006, a RS decoder 4007, and aderandomizer 4008. The demodulating unit may further include an RSdecoder 4009 and a derandomizer 4010. The demodulating unit may furtherinclude a TCM decoder 4011, a time interleaver 4012, RS decoder 4013,and derandomizer 4014.

More specifically, when a tuner tunes to a frequency of a specificchannel having main service data and mobile service data multiplexedtherein. Thereafter, the tuned frequency of the specific physicalchannel is down-converted to an intermediate frequency (IF) signal,thereby being inputted to the demodulator 4002. The demodulator 4002performs self-gain control, carrier recovery, and timing recoveryprocesses on the inputted IF signal, thereby modifying the inputted IFsignal to a baseband signal. Then, the demodulator 4002 outputs thebaseband signal to the equalizer 4003.

The known sequence detector 4004 detects the known sequence placeinserted by the transmitting system from the input/output data of thedemodulator 4002 (i.e., the data prior to the demodulation process orthe data after the demodulation process). Thereafter, the known sequencedetector 4004 outputs the place information along with the symbolsequence of the known data, which are generated from the detected place,to the demodulator 4002 and the equalizer 4003. Also, the known sequencedetector 4004 may detect MPH-associated information from the output ofthe demodulator 4002, thereby configuring an ensemble map. Then, theknown sequence detector 4004 refers to the ensemble map, so as to outputknown data place information and field synchronization place informationin the ensemble including a user-selected service. The MPH-associatedinformation may include sub-frame count information, slot countinformation, ensemble_id information, SGN information, NOG information,ETP information, and so on.

The demodulating unit further includes a power controller (not shown)and may refer to the ensemble map so as to control the power of thetuner and the demodulating unit. For example, the power controller turnsthe power on, so as to receive data, only during a section having a datagroup of an ensemble including user-requested mobile service allocated(or assigned) thereto. Alternatively, the power controller turns thepower off during the remaining sections, thereby reducing excessivepower consumption.

Furthermore, the known sequence detector 4004 outputs informationenabling the turbo decoder 4005 to identify the mobile service data thathave been additionally encoded by the transmitting system, and the mainservice data that have not been processed with additional encoding. Theknown sequence detector 4004 outputs such identification information tothe turbo decoder 4005.

The demodulator 4002 uses the known data symbol sequence during thetiming and/or carrier recovery, thereby enhancing the demodulatingperformance. Similarly, the equalizer 4003 uses the known data so as toenhance the equalizing performance. For example, a channel impulseresponse (CIR) may be estimated, so as to perform channel equalization.Then, in accordance with a predetermined method, the equalizer 4003compensates the distortion on the channel, the distortion being includedin the demodulated signal, thereby outputting the distortion-compensateddata to the turbo decoder 4005.

When the inputted data corresponds to the mobile service data and theSIC data, the turbo decoder 4005 performs turbo-decoding on the mobileservice data and the SIC data. Alternatively, when the inputted datacorresponds to the main service data, the turbo decoder 4005 outputsdirectly the main service data to the TCM decoder 4011.

Also, according to an embodiment of the present invention, the blockdecoder of FIG. 27 may be applied as the turbo decoder 4005. The SICdata corresponds to signaling information, such as a transmissionparameter. If the mobile service data are diversity-transmitted, thesignaling information including the diversity processing informationshould be decoded before being inputted to the turbo decoder 4005.

Furthermore, the turbo-decoded diversity processing information isprovided to the turbo decoder 4005. Accordingly, the turbo decoder 4005refers to the diversity processing information, so as to turbo-decodethe mobile service data back to the initial state prior to dispersion,the mobile service data being dispersed and transmitted to time sectionsand/or frequency sections.

At this point, the turbo-decoded SIC data are outputted to the RSdecoder 4009, and the turbo-decoded mobile service data are outputted tothe time deinterleaver 4006.

The RS decoder 4009 corrects the error that has occurred in theturbo-decoded SIC data and, then, outputs the error-corrected SIC datato the derandomizer 4010. Thereafter, the derandomizer 4010 performsderandomizing on the error-corrected SIC data. According to anembodiment of the present invention, the RS decoder 4009 RS-decodes theturbo-decoded SIC data so as to perform error correction. At this point,at least one of the parity data and the CRC data may be used for theerror correction process.

The time deinterleaver 4006 performs time-deinterleaving on theturbo-decoded mobile service data, as an inverse process of thetransmitting system. Thereafter, the time deinterleaver 4006 recoversthe data scattered along the time axis back to the initial state,thereby outputting the recovered data to the RS decoder 4007. Accordingto an embodiment of the present invention, the RS decoder 4007RS-decodes the deinterleaved mobile service data, so as to perform theerror correction process.

The TCM decoder 4011 performs TCM decoding on the main service dataoutputted from the turbo decoder 4005, thereby outputting theTCM-decoded main service data to the time deinterleaver 4012. The timedeinterleaver 4012 performs time-deinterleaving on the TCM-decoded mainservice data as an inverse process of the transmitting system, therebyoutputting the processed main service data to the RS decoder 4013. TheRS decoder 4013 corrects the error that has occurred in main servicedata and, then, outputs the error-corrected main service data to thederandomizer 4014. According to an embodiment of the present invention,the RS decoder 4013 RS-decodes the deinterleaved main service data so asto perform error correction. The derandomizer 4014 then derandomizes theerror-corrected main service data.

General Receiving System

FIG. 34 illustrates a block diagram showing a structure of a receivingsystem according to an embodiment of the present invention. Herein, thedemodulating unit of FIG. 29, and FIG. 31 to FIG. 33 may be applied inthe receiving system. Referring to FIG. 34, the receiving systemincludes a tuner 6001, a demodulating unit 6002, a demultiplexer 6003,an audio decoder 6004, a video decoder 6005, a native TV applicationmanager 6006, a channel manager 6007, a channel map 6008, a first memory6009, an SI and/or data decoder 6010, a second memory 6011, a systemmanager 6012, a data broadcast application manager 6013, a storagecontroller 6014, a third memory 6015, and a GPS module 6020. Herein, thefirst memory 6009 corresponds to a non-volatile random access memory(NVRAM) (or a flash memory). The third memory 6015 corresponds to alarge-scale storage device, such as a hard disk drive (HDD), a memorychip, and so on.

The tuner 6001 tunes a frequency of a specific channel through any oneof an antenna, cable, and satellite. Then, the tuner 6001 down-convertsthe tuned frequency to an intermediate frequency (IF), which is thenoutputted to the demodulating unit 6002. At this point, the tuner 6001is controlled by the channel manager 6007. Additionally, the result andstrength of the broadcast signal of the tuned channel are also reportedto the channel manager 6007. The data that are being received by thefrequency of the tuned specific channel include main service data,mobile service data, and table data for decoding the main service dataand mobile service data.

According to the embodiment of the present invention, audio data andvideo data for mobile broadcast programs may be applied as the mobileservice data. Such audio data and video data are compressed by varioustypes of encoders so as to be transmitted to a broadcasting station. Inthis case, the video decoder 6004 and the audio decoder 6005 will beprovided in the receiving system so as to correspond to each of theencoders used for the compression process. Thereafter, the decodingprocess will be performed by the video decoder 6004 and the audiodecoder 6005. Then, the processed video and audio data will be providedto the users. Examples of the encoding/decoding scheme for the audiodata may include AC 3, MPEG 2 AUDIO, MPEG 4 AUDIO, AAC, AAC+, HE AAC,AAC SBR, MPEG-Surround, and BSAC. And, examples of the encoding/decodingscheme for the video data may include MPEG 2 VIDEO, MPEG 4 VIDEO, H.264,SVC, and VC-1.

Depending upon the embodiment of the present invention, examples of themobile service data may include data provided for data service, such asJava application data, HTML application data, XML data, and so on. Thedata provided for such data services may correspond either to a Javaclass file for the Java application, or to a directory file designatingpositions (or locations) of such files. Furthermore, such data may alsocorrespond to an audio file and/or a video file used in eachapplication. The data services may include weather forecast services,traffic information services, stock information services, servicesproviding information quiz programs providing audience participationservices, real time poll, user interactive education programs, gamingservices, services providing information on soap opera (or TV series)synopsis, characters, original sound track, filing sites, servicesproviding information on past sports matches, profiles andaccomplishments of sports players, product information and productordering services, services providing information on broadcast programsby media type, airing time, subject, and so on. The types of dataservices described above are only exemplary and are not limited only tothe examples given herein. Furthermore, depending upon the embodiment ofthe present invention, the mobile service data may correspond to metadata. For example, the meta data be written in XML format so as to betransmitted through a DSM-CC protocol.

The demodulating unit 6002 performs VSB-demodulation and channelequalization on the signal being outputted from the tuner 6001, therebyidentifying the main service data and the mobile service data.Thereafter, the identified main service data and mobile service data areoutputted in TS packet units. An example of the demodulating unit 6002is shown in FIG. 27 and FIG. 31 to FIG. 33. Therefore, the structure andoperation of the demodulator will be described in detail in a laterprocess. However, this is merely exemplary and the scope of the presentinvention is not limited to the example set forth herein. In theembodiment given as an example of the present invention, only the mobileservice data packet outputted from the demodulating unit 6002 isinputted to the demultiplexer 6003. In this case, the main service datapacket is inputted to another demultiplexer (not shown) that processesmain service data packets. Herein, the storage controller 6014 is alsoconnected to the other demultiplexer in order to store the main servicedata after processing the main service data packets. The demultiplexerof the present invention may also be designed to process both mobileservice data packets and main service data packets in a singledemultiplexer.

The storage controller 6014 is interfaced with the demultipelxer so asto control instant recording, reserved (or pre-programmed) recording,time shift, and so on of the mobile service data and/or main servicedata. For example, when one of instant recording, reserved (orpre-programmed) recording, and time shift is set and programmed in thereceiving system (or receiver) shown in FIG. 34, the correspondingmobile service data and/or main service data that are inputted to thedemultiplexer are stored in the third memory 6015 in accordance with thecontrol of the storage controller 6014. The third memory 6015 may bedescribed as a temporary storage area and/or a permanent storage area.Herein, the temporary storage area is used for the time shiftingfunction, and the permanent storage area is used for a permanent storageof data according to the user's choice (or decision).

When the data stored in the third memory 6015 need to be reproduced (orplayed), the storage controller 6014 reads the corresponding data storedin the third memory 6015 and outputs the read data to the correspondingdemultiplexer (e.g., the mobile service data are outputted to thedemultiplexer 6003 shown in FIG. 34). At this point, according to theembodiment of the present invention, since the storage capacity of thethird memory 6015 is limited, the compression encoded mobile servicedata and/or main service data that are being inputted are directlystored in the third memory 6015 without any modification for theefficiency of the storage capacity. In this case, depending upon thereproduction (or reading) command, the data read from the third memory6015 pass trough the demultiplexer so as to be inputted to thecorresponding decoder, thereby being restored to the initial state.

The storage controller 6014 may control the reproduction (or play),fast-forward, rewind, slow motion, instant replay functions of the datathat are already stored in the third memory 6015 or presently beingbuffered. Herein, the instant replay function corresponds to repeatedlyviewing scenes that the viewer (or user) wishes to view once again. Theinstant replay function may be performed on stored data and also on datathat are currently being received in real time by associating theinstant replay function with the time shift function. If the data beinginputted correspond to the analog format, for example, if thetransmission mode is NTSC, PAL, and so on, the storage controller 6014compression encodes the inputted data and stored the compression-encodeddata to the third memory 6015. In order to do so, the storage controller6014 may include an encoder, wherein the encoder may be embodied as oneof software, middleware, and hardware. Herein, an MPEG encoder may beused as the encoder according to an embodiment of the present invention.The encoder may also be provided outside of the storage controller 6014.

Meanwhile, in order to prevent illegal duplication (or copies) of theinput data being stored in the third memory 6015, the storage controller6014 scrambles (or encrypts) the input data and stores the scrambled (orencrypted) data in the third memory 6015. Accordingly, the storagecontroller 6014 may include a scramble algorithm (or encryptionalgorithm) for scrambling the data stored in the third memory 6015 and adescramble algorithm (or decryption algorithm) for descrambling (ordecrypting) the data read from the third memory 6015. The scramblingmethod may include using an arbitrary key (e.g., control word) to modifya desired set of data, and also a method of mixing signals.

Meanwhile, the demultiplexer 6003 receives the real-time data outputtedfrom the demodulating unit 6002 or the data read from the third memory6015 and demultiplexes the received data. In the example given in thepresent invention, the demultiplexer 6003 performs demultiplexing on themobile service data packet. Therefore, in the present invention, thereceiving and processing of the mobile service data will be described indetail. However, depending upon the many embodiments of the presentinvention, not only the mobile service data but also the main servicedata may be processed by the demultiplexer 6003, the audio decoder 6004,the video decoder 6005, the native TV application manager 6006, thechannel manager 6007, the channel map 6008, the first memory 6009, theSI and/or data decoder 6010, the second memory 6011, a system manager6012, the data broadcast application manager 6013, the storagecontroller 6014, the third memory 6015, and the GPS module 6020.Thereafter, the processed data may be used to provide diverse servicesto the users.

The demultiplexer 6003 demultiplexes mobile service data and systeminformation (SI) tables from the mobile service data packet inputted inaccordance with the control of the SI and/or data decoder 6010.Thereafter, the demultiplexed mobile service data and SI tables areoutputted to the SI and/or data decoder 6010 in a section format. Inthis case, it is preferable that data for the data service are used asthe mobile service data that are inputted to the SI and/or data decoder6010. In order to extract the mobile service data from the channelthrough which mobile service data are transmitted and to decode theextracted mobile service data, system information is required. Suchsystem information may also be referred to as service information. Thesystem information may include channel information, event information,etc. In the embodiment of the present invention, the PSI/PSIP tables areapplied as the system information. However, the present invention is notlimited to the example set forth herein. More specifically, regardlessof the name, any protocol transmitting system information in a tableformat may be applied in the present invention.

The PSI table is an MPEG-2 system standard defined for identifying thechannels and the programs. The PSIP table is an advanced televisionsystems committee (ATSC) standard that can identify the channels and theprograms. The PSI table may include a program association table (PAT), aconditional access table (CAT), a program map table (PMT), and a networkinformation table (NIT). Herein, the PAT corresponds to specialinformation that is transmitted by a data packet having a PID of ‘0’.The PAT transmits PID information of the PMT and PID information of theNIT corresponding to each program. The CAT transmits information on apaid broadcast system used by the transmitting system. The PMT transmitsPID information of a transport stream (TS) packet, in which programidentification numbers and individual bit sequences of video and audiodata configuring the corresponding program are transmitted, and the PIDinformation, in which PCR is transmitted. The NIT transmits informationof the actual transmission network.

The PSIP table may include a virtual channel table (VCT), a system timetable (STT), a rating region table (RRT), an extended text table (ETT),a direct channel change table (DCCT), an event information table (EIT),and a master guide table (MGT).

The VCT transmits information on virtual channels, such as channelinformation for selecting channels and information such as packetidentification (PID) numbers for receiving the audio and/or video data.More specifically, when the VCT is parsed, the PID of the audio/videodata of the broadcast program may be known. Herein, the correspondingaudio/video data are transmitted within the channel along with thechannel name and the channel number.

The VCT is configured by including at least one of a table_id field, asection_syntax_indicator field, a private_indicator field, asection_length field, a transport_stream_id field, a version_numberfield, a current_next_indicator field, a section_number field, alast_section_number field, a protocol_version field, and anum_channels_in_section field.

The VCT syntax further includes a first ‘for’ loop repetition statementthat is repeated as much as the num_channels_in_section field value. Thefirst repetition statement may include at least one of a short_namefield, a major_channel_number field, a minor_channel_number field, amodulation_mode field, a carrier_frequency field, a channel_TSID field,a program_number field, an ETM_location field, an access_controlledfield, a hidden field, a service_type field, a source_id field, adescriptor_length field, and a second ‘for’ loop statement that isrepeated as much as the number of descriptors included in the firstrepetition statement. Herein, the second repetition statement will bereferred to as a first descriptor loop for simplicity. The descriptordescriptors( ) included in the first descriptor loop is separatelyapplied to each virtual channel.

Furthermore, the VCT syntax may further include anadditional_descriptor_length field, and a third ‘for’ loop statementthat is repeated as much as the number of descriptors additionally addedto the VCT. For simplicity of the description of the present invention,the third repetition statement will be referred to as a seconddescriptor loop. The descriptor additional_descriptors( ) included inthe second descriptor loop is commonly applied to all virtual channelsdescribed in the VCT.

As described above, the table_id field indicates a unique identifier (oridentification) (ID) that can identify the information being transmittedto the table as the VCT. More specifically, the table_id field indicatesa value informing that the table corresponding to this section is a VCT.For example, a 0×C8 value may be given to the table_id field.

The version_number field indicates the version number of the VCT. Thesection_number field indicates the number of this section. Thelast_section_number field indicates the number of the last section of acomplete VCT. And, the num_channel_in_section field designates thenumber of the overall virtual channel existing within the VCT section.Furthermore, in the first ‘for’ loop repetition statement, theshort_name field indicates the name of a virtual channel. Themajor_channel_number field indicates a ‘major’ channel number associatedwith the virtual channel defined within the first repetition statement,and the minor_channel_number field indicates a ‘minor’ channel number.More specifically, each of the channel numbers should be connected tothe major and minor channel numbers, and the major and minor channelnumbers are used as user reference numbers for the corresponding virtualchannel.

The program_number field is shown for connecting the virtual channelhaving an MPEG-2 program association table (PAT) and program map table(PMT) defined therein, and the program_number field matches the programnumber within the PAT/PMT. Herein, the PAT describes the elements of aprogram corresponding to each program number, and the PAT indicates thePID of a transport packet transmitting the PMT. The PMT describedsubordinate information, and a PID list of the transport packet throughwhich a program identification number and a separate bit sequence, suchas video and/or audio data configuring the program, are beingtransmitted.

The service_type field indicates the service type provided in acorresponding virtual channel. It is provided that the service_typefield should only indicate an analog television, a digital television,digital audio data, and digital video data. Also, according to theembodiment of the present invention, it may be provided that a mobilebroadcast program should be designated to the service_type field. Theservice_type field, which is parsed by the SI and/or data decoder 6010may be provided to a receiving system, as shown in FIG. 34, and usedaccordingly. According to other embodiments of the present invention,the parsed service_type field may also be provided to each of the audiodecoder 6004 and video decoder 6005, so as to be used in the decodingprocess.

The source_id field indicates a program source connected to thecorresponding virtual channel. Herein, a source refers to a specificsource, such as an image, a text, video data, or sound. The source_-idfield value has a unique value within the transport stream transmittingthe VCT. Meanwhile, a service location descriptor may be included in adescriptor loop (i.e., descriptor{ }) within a next ‘for’ looprepetition statement. The service location descriptor may include astream type, PID, and language code for each elementary stream.

The service location descriptor may include a descriptor_tag field, adescriptor_length field, and a PCR_PID field. Herein, the PCR_PID fieldindicates the PID of a transport stream packet within a programspecified by a program_number field, wherein the transport stream packetincludes a valid PCR field. Meanwhile, the service location descriptorincludes a number_elements field so as to indicate a number of PIDs usedin the corresponding program. The number of repetition of a next ‘for’descriptor loop repetition statement can be decided, depending upon thevalue of the number_elements field. The ‘for’ loop repetition statementincludes a stream_type field, an elementary_PID field, and anISO_(—)639_language_code field. Herein, the stream_type field indicatesthe stream type of the corresponding elementary stream (i.e.,video/audio data). The elementary_PID field indicates the PID of thecorresponding elementary stream. The ISO_(—)639_language_code fieldindicates a language code of the corresponding elementary stream.

ISO/IEC 11172 Video, ITU-T Rec. H.262 | ISO/IEC 13818-2 Video or ISO/IEC11172-2 constrained parameter video stream, ISO/IEC 11172 Audio, ISO/IEC13818-3 Audio, ITU-T Rec. H.222.0 | ISO/IEC 13818-1 private_sections,ITU-T Rec. H.222.0 | ISO/IEC 13818-1 PES packets containing privatedata, ISO/IEC 13522 MHEG, ITU-T Rec. H.222.0 | ISO/IEC 13818-1 Annex ADSM CC, ITU-T Rec. H.222.1, ISO/IEC 13818-6 type A, ISO/IEC 13818-6 typeB, ISO/IEC 13818-6 type C, ISO/IEC 13818-6 type D, ISO/IEC 13818-1auxiliary, and so on may be applied as the stream type. Meanwhile,according to the embodiment of the present invention, MPH video stream:Non-hierarchical mode, MPH audio stream: Non-hierarchical mode, MPHNon-A/V stream: Non-hierarchical mode, MPH High Priority video stream:Hierarchical mode, MPH High Priority audio stream: Hierarchical mode,MPH Low Priority video stream: Hierarchical mode, MPH Low priority audiostream: Hierarchical mode, and so on may further be applied as thestream type.

As described above, “MPH” corresponds to the initials of “mobile”,“pedestrian”, and “handheld” and represents the opposite concept of afixed-type system. Therefore, the MPH video stream: Non-hierarchicalmode, the MPH audio stream: Non-hierarchical mode, the MPH Non-A/Vstream: Non-hierarchical mode, the MPH High Priority video stream:Hierarchical mode, the MPH High Priority audio stream: Hierarchicalmode, the MPH Low Priority video stream: Hierarchical mode, and the MPHLow priority audio stream: Hierarchical mode correspond to stream typesthat are applied when mobile broadcast programs are being transmittedand received. Also the Hierarchical mode and the Non-hierarchical modeeach correspond to values that are used in stream types having differentpriority levels. Herein, the priority level is determined based upon ahierarchical structure applied in any one of the encoding or decodingmethod.

Therefore, when a hierarchical structure-type codec is used, a fieldvalue including the hierarchical mode and the non-hierarchical mode isrespectively designated so as to identify each stream. Such stream typeinformation is parsed by the SI and/or data decoder 6010, so as to beprovided to the video and audio decoders 6004 and 6005. Thereafter, eachof the video and audio decoders 6004 and 6005 uses the parsed streamtype information in order to perform the decoding process. Other streamtypes that may be applied in the present invention may include MPEG 4AUDIO, AC 3, AAC, AAC+, BSAC, HE AAC, AAC SBR, and MPEG-S for the audiodata, and may also include MPEG 2 VIDEO, MPEG 4 VIDEO, H.264, SVC, andVC-1 for the video data.

Furthermore, in fields using the hierarchical mode and thenon-hierarchical mode, such as the MPH video stream: Non-hierarchicalmode and the MPH audio stream: Non-hierarchical mode, examples of usingthe MPEG 4 AUDIO, AC 3, AAC, AAC+, BSAC, HE AAC, AAC SBR, and MPEG-S forthe audio data, and the MPEG 2 VIDEO, MPEG 4 VIDEO, H.264, SVC, and VC-1for the video data may also be respectively used as replacements foreach of the audio stream and the video stream may be considered as otherembodiments of the present invention and may, therefore, be included inthe scope of the present invention. Meanwhile, the stream_type field maybe provided as one of the fields within the PMT. And, in this case, itis apparent that such stream_type field includes the above-describedsyntax. The STT transmits information on the current data and timinginformation. The RRT transmits information on region and consultationorgans for program ratings. The ETT transmits additional description ofa specific channel and broadcast program. The EIT transmits informationon virtual channel events (e.g., program title, program start time,etc.).

Finally, the DCCT/DCCSCT transmits information associated with automatic(or direct) channel change. And, the MGT transmits the versions and PIDinformation of the above-mentioned tables included in the PSIP. Each ofthe above-described tables included in the PSI/PSIP is configured of abasic unit referred to as a “section”, and a combination of one or moresections forms a table. For example, the VCT may be divided into 256sections. Herein, one section may include a plurality of virtual channelinformation. However, a single set of virtual channel information is notdivided into two or more sections. At this point, the receiving systemmay parse and decode the data for the data service that are transmittingby using only the tables included in the PSI, or only the tablesincluded in the PSIP, or a combination of tables included in both thePSI and the PSIP. In order to parse and decode the mobile service data,at least one of the PAT and PMT included in the PSI, and the VCTincluded in the PSIP is required. For example, the PAT may include thesystem information for transmitting the mobile service data, and the PIDof the PMT corresponding to the mobile service data (or program number).The PMT may include the PID of the TS packet used for transmitting themobile service data. The VCT may include information on the virtualchannel for transmitting the mobile service data, and the PID of the TSpacket for transmitting the mobile service data.

Meanwhile, depending upon the embodiment of the present invention, aDVB-SI may be applied instead of the PSIP. The DVB-SI may include anetwork information table (NIT), a service description table (SDT), anevent information table (EIT), and a time and data table (TDT). TheDVB-SI may be used in combination with the above-described PSI. Herein,the NIT divides the services corresponding to particular networkproviders by specific groups. The NIT includes all tuning informationthat are used during the IRD set-up. The NIT may be used for informingor notifying any change in the tuning information. The SDT includes theservice name and different parameters associated with each servicecorresponding to a particular MPEG multiplex. The EIT is used fortransmitting information associated with all events occurring in theMPEG multiplex. The EIT includes information on the current transmissionand also includes information selectively containing differenttransmission streams that may be received by the IRD. And, the TDT isused for updating the clock included in the IRD.

Furthermore, three selective SI tables (i.e., a bouquet associate table(BAT), a running status table (RST), and a stuffing table (ST)) may alsobe included. More specifically, the bouquet associate table (BAT)provides a service grouping method enabling the IRD to provide servicesto the viewers. Each specific service may belong to at least one‘bouquet’ unit. A running status table (RST) section is used forpromptly and instantly updating at least one event execution status. Theexecution status section is transmitted only once at the changing pointof the event status. Other SI tables are generally transmitted severaltimes. The stuffing table (ST) may be used for replacing or discarding asubsidiary table or the entire SI tables.

In the present invention, when the mobile service data correspond toaudio data and video data, it is preferable that the mobile service dataincluded (or loaded) in a payload within a TS packet correspond to PEStype mobile service data. According to another embodiment of the presentinvention, when the mobile service data correspond to the data for thedata service (or data service data), the mobile service data included inthe payload within the TS packet consist of a digital storagemedia-command and control (DSM-CC) section format. However, the TSpacket including the data service data may correspond either to apacketized elementary stream (PES) type or to a section type. Morespecifically, either the PES type data service data configure the TSpacket, or the section type data service data configure the TS packet.The TS packet configured of the section type data will be given as theexample of the present invention. At this point, the data service dataare includes in the digital storage media-command and control (DSM-CC)section. Herein, the DSM-CC section is then configured of a 188-byteunit TS packet.

Furthermore, the packet identification of the TS packet configuring theDSM-CC section is included in a data service table (DST). Whentransmitting the DST, ‘0×95’ is assigned as the value of a stream-typefield included in the service location descriptor of the PMT or the VCT.More specifically, when the PMT or VCT stream_type field value is‘0×95’, the receiving system may acknowledge the reception of the databroadcast program including mobile service data. At this point, themobile service data may be transmitted by a data/object carousel method.The data/object carousel method corresponds to repeatedly transmittingidentical data on a regular basis.

At this point, according to the control of the SI and/or data decoder6010, the demultiplexer 6003 performs section filtering, therebydiscarding repetitive sections and outputting only the non-repetitivesections to the SI and/or data decoder 6010. The demultiplexer 6003 mayalso output only the sections configuring desired tables (e.g., VCT orEIT) to the SI and/or data decoder 6010 by section filtering. Herein,the VCT or EIT may include a specific descriptor for the mobile servicedata. However, the present invention does not exclude the possibilitiesof the mobile service data being included in other tables, such as thePMT. The section filtering method may include a method of verifying thePID of a table defined by the MGT, such as the VCT, prior to performingthe section filtering process. Alternatively, the section filteringmethod may also include a method of directly performing the sectionfiltering process without verifying the MGT, when the VCT includes afixed PID (i.e., a base PID). At this point, the demultiplexer 6003performs the section filtering process by referring to a table_id field,a version_number field, a section_number field, etc.

As described above, the method of defining the PID of the VCT broadlyincludes two different methods. Herein, the PID of the VCT is a packetidentifier required for identifying the VCT from other tables. The firstmethod consists of setting the PID of the VCT so that it is dependent tothe MGT. In this case, the receiving system cannot directly verify theVCT among the many PSI and/or PSIP tables. Instead, the receiving systemmust check the PID defined in the MGT in order to read the VCT. Herein,the MGT defines the PID, size, version number, and so on, of diversetables. The second method consists of setting the PID of the VCT so thatthe PID is given a base PID value (or a fixed PID value), thereby beingindependent from the MGT. In this case, unlike in the first method, theVCT according to the present invention may be identified without havingto verify every single PID included in the MGT. Evidently, an agreementon the base PID must be previously made between the transmitting systemand the receiving system.

Meanwhile, in the embodiment of the present invention, the demultiplexer6003 may output only an application information table (AIT) to the SIand/or data decoder 6010 by section filtering. The AIT includesinformation on an application being operated in the receiver for thedata service. The AIT may also be referred to as an XAIT, and an AMT.Therefore, any table including application information may correspond tothe following description. When the AIT is transmitted, a value of‘0×05’ may be assigned to a stream_type field of the PMT. The AIT mayinclude application information, such as application name, applicationversion, application priority, application ID, application status (i.e.,auto-start, user-specific settings, kill, etc.), application type (i.e.,Java or HTML), position (or location) of stream including applicationclass and data files, application platform directory, and location ofapplication icon.

In the method for detecting application information for the data serviceby using the AIT, component_tag, original_network_id,transport_stream_id, and service_id fields may be used for detecting theapplication information. The component_tag field designates anelementary stream carrying a DSI of a corresponding object carousel. Theoriginal_network_id field indicates a DVB-SI original_network_id of theTS providing transport connection. The transport_stream_id fieldindicates the MPEG TS of the TS providing transport connection, and theservice_id field indicates the DVB-SI of the service providing transportconnection. Information on a specific channel may be obtained by usingthe original_network_id field, the transport_stream_id field, and theservice_id field. The data service data, such as the application data,detected by using the above-described method may be stored in the secondmemory 6011 by the SI and/or data decoder 6010.

The SI and/or data decoder 6010 parses the DSM-CC section configuringthe demultiplexed mobile service data. Then, the mobile service datacorresponding to the parsed result are stored as a database in thesecond memory 6011. The SI and/or data decoder 6010 groups a pluralityof sections having the same table identification (table_id) so as toconfigure a table, which is then parsed. Thereafter, the parsed resultis stored as a database in the second memory 6011. At this point, byparsing data and/or sections, the SI and/or data decoder 6010 reads allof the remaining actual section data that are not section-filtered bythe demultiplexer 6003. Then, the SI and/or data decoder 6010 stores theread data to the second memory 6011. The second memory 6011 correspondsto a table and data/object carousel database storing system informationparsed from tables and mobile service data parsed from the DSM-CCsection. Herein, a table_id field, a section_number field, and alast_section_number field included in the table may be used to indicatewhether the corresponding table is configured of a single section or aplurality of sections. For example, TS packets having the PID of the VCTare grouped to form a section, and sections having table identifiersallocated to the VCT are grouped to form the VCT. When the VCT isparsed, information on the virtual channel to which mobile service dataare transmitted may be obtained.

Also, according to the present invention, the SI and/or data decoder6010 parses the SLD of the VCT, thereby transmitting the stream typeinformation of the corresponding elementary stream to the audio decoder6004 or the video decoder 6005. In this case, the corresponding audiodecoder 6004 or video decoder 6005 uses the transmitted stream typeinformation so as to perform the audio or video decoding process.Furthermore, according to the present invention, the SI and/or datadecoder 6010 parses an AC-3 audio descriptor, an MPEG 2 audiodescriptor, an MPEG 4 audio descriptor, an AAC descriptor, an AAC+descriptor, an HE AAC descriptor, an AAC SBR descriptor, an MPEGsurround descriptor, a BSAC descriptor, an MPEG 2 video descriptor, anMPEG 4 video descriptor, an H.264 descriptor, an SVC descriptor, a VC-1descriptor, and so on, of the EIT, thereby transmitting the audio orvideo codec information of the corresponding event to the audio decoder6004 or video decoder 6005. In this case, the corresponding audiodecoder 6004 or video decoder 6005 uses the transmitted audio or videocodec information in order to perform an audio or video decodingprocess.

The obtained application identification information, service componentidentification information, and service information corresponding to thedata service may either be stored in the second memory 6011 or beoutputted to the data broadcasting application manager 6013. Inaddition, reference may be made to the application identificationinformation, service component identification information, and serviceinformation in order to decode the data service data. Alternatively,such information may also prepare the operation of the applicationprogram for the data service. Furthermore, the SI and/or data decoder6010 controls the demultiplexing of the system information table, whichcorresponds to the information table associated with the channel andevents. Thereafter, an A/V PID list may be transmitted to the channelmanager 6007.

The channel manager 6007 may refer to the channel map 6008 in order totransmit a request for receiving system-related information data to theSI and/or data decoder 6010, thereby receiving the corresponding result.In addition, the channel manager 6007 may also control the channeltuning of the tuner 6001. Furthermore, the channel manager 6007 maydirectly control the demultiplexer 6003, so as to set up the A/V PID,thereby controlling the audio decoder 6004 and the video decoder 6005.

The audio decoder 6004 and the video decoder 6005 may respectivelydecode and output the audio data and video data demultiplexed from themain service data packet. Alternatively, the audio decoder 6004 and thevideo decoder 6005 may respectively decode and output the audio data andvideo data demultiplexed from the mobile service data packet. Meanwhile,when the mobile service data include data service data, and also audiodata and video data, it is apparent that the audio data and video datademultiplexed by the demultiplexer 6003 are respectively decoded by theaudio decoder 6004 and the video decoder 6005. For example, anaudio-coding (AC)-3 decoding algorithm, an MPEG-2 audio decodingalgorithm, an MPEG-4 audio decoding algorithm, an AAC decodingalgorithm, an AAC+ decoding algorithm, an HE AAC decoding algorithm, anAAC SBR decoding algorithm, an MPEG surround decoding algorithm, and aBSAC decoding algorithm may be applied to the audio decoder 6004. Also,an MPEG-2 video decoding algorithm, an MPEG-4 video decoding algorithm,an H.264 decoding algorithm, an SVC decoding algorithm, and a VC-1decoding algorithm may be applied to the video decoder 6005.Accordingly, the decoding process may be performed.

Meanwhile, the native TV application manager 6006 operates a nativeapplication program stored in the first memory 6009, thereby performinggeneral functions such as channel change. The native application programrefers to software stored in the receiving system upon shipping of theproduct. More specifically, when a user request (or command) istransmitted to the receiving system through a user interface (UI), thenative TV application manger 6006 displays the user request on a screenthrough a graphic user interface (GUI), thereby responding to the user'srequest. The user interface receives the user request through an inputdevice, such as a remote controller, a key pad, a jog controller, an atouch-screen provided on the screen, and then outputs the received userrequest to the native TV application manager 6006 and the databroadcasting application manager 6013. Furthermore, the native TVapplication manager 6006 controls the channel manager 6007, therebycontrolling channel-associated operations, such as the management of thechannel map 6008, and controlling the SI and/or data decoder 6010. Thenative TV application manager 6006 also controls the GUI of the overallreceiving system, thereby storing the user request and status of thereceiving system in the first memory 6009 and restoring the storedinformation.

The channel manager 6007 controls the tuner 6001 and the SI and/or datadecoder 6010, so as to managing the channel map 6008 so that it canrespond to the channel request made by the user. More specifically,channel manager 6007 sends a request to the SI and/or data decoder 6010so that the tables associated with the channels that are to be tuned areparsed. The results of the parsed tables are reported to the channelmanager 6007 by the SI and/or data decoder 6010. Thereafter, based onthe parsed results, the channel manager 6007 updates the channel map6008 and sets up a PID in the demultiplexer 6003 for demultiplexing thetables associated with the data service data from the mobile servicedata.

The system manager 6012 controls the booting of the receiving system byturning the power on or off. Then, the system manager 6012 stores ROMimages (including downloaded software images) in the first memory 6009.More specifically, the first memory 6009 stores management programs suchas operating system (OS) programs required for managing the receivingsystem and also application program executing data service functions.The application program is a program processing the data service datastored in the second memory 6011 so as to provide the user with the dataservice. If the data service data are stored in the second memory 6011,the corresponding data service data are processed by the above-describedapplication program or by other application programs, thereby beingprovided to the user. The management program and application programstored in the first memory 6009 may be updated or corrected to a newlydownloaded program. Furthermore, the storage of the stored managementprogram and application program is maintained without being deleted evenif the power of the system is shut down. Therefore, when the power issupplied, the programs may be executed without having to be newlydownloaded once again.

The application program for providing data service according to thepresent invention may either be initially stored in the first memory6009 upon the shipping of the receiving system, or be stored in thefirst memory 6009 after being downloaded. The application program forthe data service (i.e., the data service providing application program)stored in the first memory 6009 may also be deleted, updated, andcorrected. Furthermore, the data service providing application programmay be downloaded and executed along with the data service data eachtime the data service data are being received.

When a data service request is transmitted through the user interface,the data broadcasting application manager 6013 operates thecorresponding application program stored in the first memory 6009 so asto process the requested data, thereby providing the user with therequested data service. And, in order to provide such data service, thedata broadcasting application manager 6013 supports the graphic userinterface (GUI). Herein, the data service may be provided in the form oftext (or short message service (SMS)), voice message, still image, andmoving image. The data broadcasting application manager 6013 may beprovided with a platform for executing the application program stored inthe first memory 6009. The platform may be, for example, a Java virtualmachine for executing the Java program. Hereinafter, an example of thedata broadcasting application manager 6013 executing the data serviceproviding application program stored in the first memory 6009, so as toprocess the data service data stored in the second memory 6011, therebyproviding the user with the corresponding data service will now bedescribed in detail.

Assuming that the data service corresponds to a traffic informationservice, the data service according to the present invention is providedto the user of a receiver that is not equipped with an electronic mapand/or a GPS system in the form of at least one of a text (or shortmessage service (SMS)), a voice message, a graphic message, a stillimage, and a moving image. In this case, when a GPS module 6020 ismounted on the receiving system, as shown in FIG. 34, the GPS module6020 receives satellite signals transmitted from a plurality of lowearth orbit satellites and extracts the current position (or location)information (e.g., longitude, latitude, altitude), thereby outputtingthe extracted information to the data broadcasting application manager6013.

At this point, it is assumed that the electronic map includinginformation on each link and nod and other diverse graphic informationare stored in one of the second memory 6011, the first memory 6009, andanother memory that is not shown. More specifically, according to therequest made by the data broadcasting application manager 6013, the dataservice data stored in the second memory 6011 are read and inputted tothe data broadcasting application manager 6013. The data broadcastingapplication manager 6013 translates (or deciphers) the data service dataread from the second memory 6011, thereby extracting the necessaryinformation according to the contents of the message and/or a controlsignal. In other words, the data broadcasting application manager 6013uses the current position information and the graphic information, sothat the current position information can be processed and provided tothe user in a graphic format.

FIG. 35 illustrates a block diagram showing the structure of a digitalbroadcast (or television) receiving system according to anotherembodiment of the present invention. Referring to FIG. 35, the receivingsystem includes a tuner 7001, a demodulating unit 7002, a demultiplexer7003, a first descrambler 7004, an audio decoder 7005, a video decoder7006, a second descrambler 7007, an authentication unit 7008, a nativeTV application manager 7009, a channel manager 7010, a channel map 7011,a first memory 7012, a data decoder 7013, a second memory 7014, a systemmanager 7015, a data broadcasting application manager 7016, a storagecontroller 7017, a third memory 7018, a telecommunication module 7019,and a GPS module 7020. Herein, the third memory 7018 is a mass storagedevice, such as a hard disk drive (HDD) or a memory chip. Also, duringthe description of the digital broadcast (or television or DTV)receiving system shown in FIG. 35, the components that are identical tothose of the receiving system of FIG. 34 will be omitted for simplicity.

As described above, in order to provide services for preventing illegalduplication (or copies) or illegal viewing of the enhanced data and/ormain data that are transmitted by using a broadcast network, and toprovide paid broadcast services, the transmitting system may generallyscramble and transmit the broadcast contents. Therefore, the receivingsystem needs to descramble the scrambled broadcast contents in order toprovide the user with the proper broadcast contents. Furthermore, thereceiving system may generally be processed with an authenticationprocess with an authentication means before the descrambling process.Hereinafter, the receiving system including an authentication means anda descrambling means according to an embodiment of the present inventionwill now be described in detail.

According to the present invention, the receiving system may be providedwith a descrambling means receiving scrambled broadcasting contents andan authentication means authenticating (or verifying) whether thereceiving system is entitled to receive the descrambled contents.Hereinafter, the descrambling means will be referred to as first andsecond descramblers 7004 and 7007, and the authentication means will bereferred to as an authentication unit 7008. Such naming of thecorresponding components is merely exemplary and is not limited to theterms suggested in the description of the present invention. Forexample, the units may also be referred to as a decryptor. Although FIG.35 illustrates an example of the descramblers 7004 and 7007 and theauthentication unit 7008 being provided inside the receiving system,each of the descramblers 7004 and 7007 and the authentication unit 7008may also be separately provided in an internal or external module.Herein, the module may include a slot type, such as a SD or CF memory, amemory stick type, a USB type, and so on, and may be detachably fixed tothe receiving system.

As described above, when the authentication process is performedsuccessfully by the authentication unit 7008, the scrambled broadcastingcontents are descrambled by the descramblers 7004 and 7007, therebybeing provided to the user. At this point, a variety of theauthentication method and descrambling method may be used herein.However, an agreement on each corresponding method should be madebetween the receiving system and the transmitting system. Hereinafter,the authentication and descrambling methods will now be described, andthe description of identical components or process steps will be omittedfor simplicity.

The receiving system including the authentication unit 7008 and thedescramblers 7004 and 7007 will now be described in detail. Thereceiving system receives the scrambled broadcasting contents throughthe tuner 7001 and the demodulating unit 7002. Then, the system manager7015 decides whether the received broadcasting contents have beenscrambled. Herein, the demodulating unit 7002 may be included as ademodulating means according to embodiment of the present invention asdescribed in FIG. 27 and FIG. 31 to FIG. 33. However, the presentinvention is not limited to the examples given in the description setforth herein. If the system manager 7015 decides that the receivedbroadcasting contents have been scrambled, then the system manager 7015controls the system to operate the authentication unit 7008. Asdescribed above, the authentication unit 7008 performs an authenticationprocess in order to decide whether the receiving system according to thepresent invention corresponds to a legitimate host entitled to receivethe paid broadcasting service. Herein, the authentication process mayvary in accordance with the authentication methods.

For example, the authentication unit 7008 may perform the authenticationprocess by comparing an IP address of an IP datagram within the receivedbroadcasting contents with a specific address of a corresponding host.At this point, the specific address of the corresponding receivingsystem (or host) may be a MAC address. More specifically, theauthentication unit 7008 may extract the IP address from thedecapsulated IP datagram, thereby obtaining the receiving systeminformation that is mapped with the IP address. At this point, thereceiving system should be provided, in advance, with information (e.g.,a table format) that can map the IP address and the receiving systeminformation. Accordingly, the authentication unit 7008 performs theauthentication process by determining the conformity between the addressof the corresponding receiving system and the system information of thereceiving system that is mapped with the IP address. In other words, ifthe authentication unit 7008 determines that the two types ofinformation conform to one another, then the authentication unit 7008determines that the receiving system is entitled to receive thecorresponding broadcasting contents.

In another example, standardized identification information is definedin advance by the receiving system and the transmitting system. Then,the identification information of the receiving system requesting thepaid broadcasting service is transmitted by the transmitting system.Thereafter, the receiving system determines whether the receivedidentification information conforms with its own unique identificationnumber, so as to perform the authentication process. More specifically,the transmitting system creates a database for storing theidentification information (or number) of the receiving systemrequesting the paid broadcasting service. Then, if the correspondingbroadcasting contents are scrambled, the transmitting system includesthe identification information in the EMM, which is then transmitted tothe receiving system.

If the corresponding broadcasting contents are scrambled, messages(e.g., entitlement control message (ECM), entitlement management message(EMM)), such as the CAS information, mode information, message positioninformation, that are applied to the scrambling of the broadcastingcontents are transmitted through a corresponding data header or antherdata packet. The ECM may include a control word (CW) used for scramblingthe broadcasting contents. At this point, the control word may beencoded with an authentication key. The EMM may include anauthentication key and entitlement information of the correspondingdata. Herein, the authentication key may be encoded with a receivingsystem-specific distribution key. In other words, assuming that theenhanced data are scrambled by using the control word, and that theauthentication information and the descrambling information aretransmitted from the transmitting system, the transmitting systemencodes the CW with the authentication key and, then, includes theencoded CW in the entitlement control message (ECM), which is thentransmitted to the receiving system. Furthermore, the transmittingsystem includes the authentication key used for encoding the CW and theentitlement to receive data (or services) of the receiving system (i.e.,a standardized serial number of the receiving system that is entitled toreceive the corresponding broadcasting service or data) in theentitlement management message (EMM), which is then transmitted to thereceiving system.

Accordingly, the authentication unit 7008 of the receiving systemextracts the identification information of the receiving system and theidentification information included in the EMM of the broadcastingservice that is being received. Then, the authentication unit 7008determines whether the identification information conform to each other,so as to perform the authentication process. More specifically, if theauthentication unit 7008 determines that the information conform to eachother, then the authentication unit 7008 eventually determines that thereceiving system is entitled to receive the request broadcastingservice.

In yet another example, the authentication unit 7008 of the receivingsystem may be detachably fixed to an external module. In this case, thereceiving system is interfaced with the external module through a commoninterface (CI). In other words, the external module may receive the datascrambled by the receiving system through the common interface, therebyperforming the descrambling process of the received data. Alternatively,the external module may also transmit only the information required forthe descrambling process to the receiving system. The common interfaceis configured on a physical layer and at least one protocol layer.Herein, in consideration of any possible expansion of the protocol layerin a later process, the corresponding protocol layer may be configuredto have at least one layer that can each provide an independentfunction.

The external module may either consist of a memory or card havinginformation on the key used for the scrambling process and otherauthentication information but not including any descrambling function,or consist of a card having the above-mentioned key information andauthentication information and including the descrambling function. Boththe receiving system and the external module should be authenticated inorder to provide the user with the paid broadcasting service provided(or transmitted) from the transmitting system. Therefore, thetransmitting system can only provide the corresponding paid broadcastingservice to the authenticated pair of receiving system and externalmodule.

Additionally, an authentication process should also be performed betweenthe receiving system and the external module through the commoninterface. More specifically, the module may communicate with the systemmanager 7015 included in the receiving system through the commoninterface, thereby authenticating the receiving system. Alternatively,the receiving system may authenticate the module through the commoninterface. Furthermore, during the authentication process, the modulemay extract the unique ID of the receiving system and its own unique IDand transmit the extracted IDs to the transmitting system. Thus, thetransmitting system may use the transmitted ID values as informationdetermining whether to start the requested service or as paymentinformation. Whenever necessary, the system manager 7015 transmits thepayment information to the remote transmitting system through thetelecommunication module 7019.

The authentication unit 7008 authenticates the corresponding receivingsystem and/or the external module. Then, if the authentication processis successfully completed, the authentication unit 7008 certifies thecorresponding receiving system and/or the external module as alegitimate system and/or module entitled to receive the requested paidbroadcasting service. In addition, the authentication unit 7008 may alsoreceive authentication-associated information from a mobiletelecommunications service provider to which the user of the receivingsystem is subscribed, instead of the transmitting system providing therequested broadcasting service. In this case, theauthentication-association information may either be scrambled by thetransmitting system providing the broadcasting service and, then,transmitted to the user through the mobile telecommunications serviceprovider, or be directly scrambled and transmitted by the mobiletelecommunications service provider. Once the authentication process issuccessfully completed by the authentication unit 7008, the receivingsystem may descramble the scrambled broadcasting contents received fromthe transmitting system. At this point, the descrambling process isperformed by the first and second descramblers 7004 and 7007. Herein,the first and second descramblers 7004 and 7007 may be included in aninternal module or an external module of the receiving system.

The receiving system is also provided with a common interface forcommunicating with the external module including the first and seconddescramblers 7004 and 7007, so as to perform the descrambling process.More specifically, the first and second descramblers 7004 and 7007 maybe included in the module or in the receiving system in the form ofhardware, middleware or software. Herein, the descramblers 7004 and 7007may be included in any one of or both of the module and the receivingsystem. If the first and second descramblers 7004 and 7007 are providedinside the receiving system, it is advantageous to have the transmittingsystem (i.e., at least any one of a service provider and a broadcaststation) scramble the corresponding data using the same scramblingmethod.

Alternatively, if the first and second descramblers 7004 and 7007 areprovided in the external module, it is advantageous to have eachtransmitting system scramble the corresponding data using differentscrambling methods. In this case, the receiving system is not requiredto be provided with the descrambling algorithm corresponding to eachtransmitting system. Therefore, the structure and size of receivingsystem may be simplified and more compact. Accordingly, in this case,the external module itself may be able to provide CA functions, whichare uniquely and only provided by each transmitting systems, andfunctions related to each service that is to be provided to the user.The common interface enables the various external modules and the systemmanager 7015, which is included in the receiving system, to communicatewith one another by a single communication method. Furthermore, sincethe receiving system may be operated by being connected with at leastone or more modules providing different services, the receiving systemmay be connected to a plurality of modules and controllers.

In order to maintain successful communication between the receivingsystem and the external module, the common interface protocol includes afunction of periodically checking the status of the oppositecorrespondent. By using this function, the receiving system and theexternal module is capable of managing the status of each oppositecorrespondent. This function also reports the user or the transmittingsystem of any malfunction that may occur in any one of the receivingsystem and the external module and attempts the recovery of themalfunction.

In yet another example, the authentication process may be performedthrough software. More specifically, when a memory card having CASsoftware downloaded, for example, and stored therein in advanced isinserted in the receiving system, the receiving system receives andloads the CAS software from the memory card so as to perform theauthentication process. In this example, the CAS software is read outfrom the memory card and stored in the first memory 7012 of thereceiving system. Thereafter, the CAS software is operated in thereceiving system as an application program. According to an embodimentof the present invention, the CAS software is mounted on (or stored) ina middleware platform and, then executed. A Java middleware will begiven as an example of the middleware included in the present invention.Herein, the CAS software should at least include information requiredfor the authentication process and also information required for thedescrambling process.

Therefore, the authentication unit 7008 performs authenticationprocesses between the transmitting system and the receiving system andalso between the receiving system and the memory card. At this point, asdescribed above, the memory card should be entitled to receive thecorresponding data and should include information on a normal receivingsystem that can be authenticated. For example, information on thereceiving system may include a unique number, such as a standardizedserial number of the corresponding receiving system. Accordingly, theauthentication unit 7008 compares the standardized serial numberincluded in the memory card with the unique information of the receivingsystem, thereby performing the authentication process between thereceiving system and the memory card.

If the CAS software is first executed in the Java middleware base, thenthe authentication between the receiving system and the memory card isperformed. For example, when the unique number of the receiving systemstored in the memory card conforms to the unique number of the receivingsystem read from the system manager 7015, then the memory card isverified and determined to be a normal memory card that may be used inthe receiving system. At this point, the CAS software may either beinstalled in the first memory 7012 upon the shipping of the presentinvention, or be downloaded to the first memory 7012 from thetransmitting system or the module or memory card, as described above.Herein, the descrambling function may be operated by the databroadcasting application manger 7016 as an application program.

Thereafter, the CAS software parses the EMM/ECM packets outputted fromthe demultiplexer 7003, so as to verify whether the receiving system isentitled to receive the corresponding data, thereby obtaining theinformation required for descrambling (i.e., the CW) and providing theobtained CW to the descramblers 7004 and 7007. More specifically, theCAS software operating in the Java middleware platform first reads outthe unique (or serial) number of the receiving system from thecorresponding receiving system and compares it with the unique number ofthe receiving system transmitted through the EMM, thereby verifyingwhether the receiving system is entitled to receive the correspondingdata. Once the receiving entitlement of the receiving system isverified, the corresponding broadcasting service information transmittedto the ECM and the entitlement of receiving the correspondingbroadcasting service are used to verify whether the receiving system isentitled to receive the corresponding broadcasting service. Once thereceiving system is verified to be entitled to receive the correspondingbroadcasting service, the authentication key transmitted to the EMM isused to decode (or decipher) the encoded CW, which is transmitted to theECM, thereby transmitting the decoded CW to the descramblers 7004 and7007. Each of the descramblers 7004 and 7007 uses the CW to descramblethe broadcasting service.

Meanwhile, the CAS software stored in the memory card may be expanded inaccordance with the paid service which the broadcast station is toprovide. Additionally, the CAS software may also include otheradditional information other than the information associated with theauthentication and descrambling. Furthermore, the receiving system maydownload the CAS software from the transmitting system so as to upgrade(or update) the CAS software originally stored in the memory card. Asdescribed above, regardless of the type of broadcast receiving system,as long as an external memory interface is provided, the presentinvention may embody a CAS system that can meet the requirements of alltypes of memory card that may be detachably fixed to the receivingsystem. Thus, the present invention may realize maximum performance ofthe receiving system with minimum fabrication cost, wherein thereceiving system may receive paid broadcasting contents such asbroadcast programs, thereby acknowledging and regarding the variety ofthe receiving system. Moreover, since only the minimum applicationprogram interface is required to be embodied in the embodiment of thepresent invention, the fabrication cost may be minimized, therebyeliminating the manufacturer's dependence on CAS manufacturers.Accordingly, fabrication costs of CAS equipments and management systemsmay also be minimized.

Meanwhile, the descramblers 7004 and 7007 may be included in the moduleeither in the form of hardware or in the form of software. In this case,the scrambled data that being received are descrambled by the module andthen demodulated. Also, if the scrambled data that are being receivedare stored in the third memory 7018, the received data may bedescrambled and then stored, or stored in the memory at the point ofbeing received and then descrambled later on prior to being played (orreproduced). Thereafter, in case scramble/descramble algorithms areprovided in the storage controller 7017, the storage controller 7017scrambles the data that are being received once again and then storesthe re-scrambled data to the third memory 7018.

In yet another example, the descrambled broadcasting contents(transmission of which being restricted) are transmitted through thebroadcasting network. Also, information associated with theauthentication and descrambling of data in order to disable thereceiving restrictions of the corresponding data are transmitted and/orreceived through the telecommunications module 7019. Thus, the receivingsystem is able to perform reciprocal (or two-way) communication. Thereceiving system may either transmit data to the telecommunicationmodule within the transmitting system or be provided with the data fromthe telecommunication module within the transmitting system. Herein, thedata correspond to broadcasting data that are desired to be transmittedto or from the transmitting system, and also unique information (i.e.,identification information) such as a serial number of the receivingsystem or MAC address.

The telecommunication module 7019 included in the receiving systemprovides a protocol required for performing reciprocal (or two-way)communication between the receiving system, which does not support thereciprocal communication function, and the telecommunication moduleincluded in the transmitting system. Furthermore, the receiving systemconfigures a protocol data unit (PDU) using a tag-length-value (TLV)coding method including the data that are to be transmitted and theunique information (or ID information). Herein, the tag field includesindexing of the corresponding PDU. The length field includes the lengthof the value field. And, the value field includes the actual data thatare to be transmitted and the unique number (e.g., identificationnumber) of the receiving system.

The receiving system may configure a platform that is equipped with theJava platform and that is operated after downloading the Javaapplication of the transmitting system to the receiving system throughthe network. In this case, a structure of downloading the PDU includingthe tag field arbitrarily defined by the transmitting system from astorage means included in the receiving system and then transmitting thedownloaded PDU to the telecommunication module 7019 may also beconfigured. Also, the PDU may be configured in the Java application ofthe receiving system and then outputted to the telecommunication module7019. The PDU may also be configured by transmitting the tag value, theactual data that are to be transmitted, the unique information of thecorresponding receiving system from the Java application and byperforming the TLV coding process in the receiving system. Thisstructure is advantageous in that the firmware of the receiving systemis not required to be changed even if the data (or application) desiredby the transmitting system is added.

The telecommunication module within the transmitting system eithertransmits the PDU received from the receiving system through a wirelessdata network or configures the data received through the network into aPDU which is transmitted to the host. At this point, when configuringthe PDU that is to be transmitted to the host, the telecommunicationmodule within the transmitting end may include unique information (e.g.,IP address) of the transmitting system which is located in a remotelocation. Additionally, in receiving and transmitting data through thewireless data network, the receiving system may be provided with acommon interface, and also provided with a WAP, CDMA 1×EV-DO, which canbe connected through a mobile telecommunication base station, such asCDMA and GSM, and also provided with a wireless LAN, mobile internet,WiBro, WiMax, which can be connected through an access point. Theabove-described receiving system corresponds to the system that is notequipped with a telecommunication function. However, a receiving systemequipped with telecommunication function does not require thetelecommunication module 7019.

The broadcasting data being transmitted and received through theabove-described wireless data network may include data required forperforming the function of limiting data reception. Meanwhile, thedemultiplexer 7003 receives either the real-time data outputted from thedemodulating unit 7002 or the data read from the third memory 7018,thereby performing demultiplexing. In this embodiment of the presentinvention, the demultiplexer 7003 performs demultiplexing on theenhanced data packet. Similar process steps have already been describedearlier in the description of the present invention. Therefore, adetailed of the process of demultiplexing the enhanced data will beomitted for simplicity.

The first descrambler 7004 receives the demultiplexed signals from thedemultiplexer 7003 and then descrambles the received signals. At thispoint, the first descrambler 7004 may receive the authentication resultreceived from the authentication unit 7008 and other data required forthe descrambling process, so as to perform the descrambling process. Theaudio decoder 7005 and the video decoder 7006 receive the signalsdescrambled by the first descrambler 7004, which are then decoded andoutputted. Alternatively, if the first descrambler 7004 did not performthe descrambling process, then the audio decoder 7005 and the videodecoder 7006 directly decode and output the received signals. In thiscase, the decoded signals are received and then descrambled by thesecond descrambler 7007 and processed accordingly.

As described above, the digital broadcasting system and data processingmethod according to the present invention have the following advantages.More specifically, the digital broadcasting system and data processingmethod according to the present invention is robust against (orresistant to) any error that may occur when transmitting mobile servicedata through a channel. And, the present invention is also highlycompatible to the conventional system. Moreover, the present inventionmay also receive the mobile service data without any error even inchannels having severe ghost effect and noise.

By inserting known data in specific positions (or places) within a dataregion, the present invention may enhance the receiving performance ofthe receiving system in an environment undergoing frequent channelchanges.

Also, by diversifying and transmitting mobile service data by timeand/or frequency, the present invention is made to be more robustagainst the burst noise than that of the related art.

Finally, the present invention is even more effective when applied tomobile and portable receivers, which are also liable to a frequentchange in channel and which require protection (or resistance) againstintense noise.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A receiving system, comprising: a receiving unit receiving abroadcast signal including mobile service data divided into a pluralityof output masses, signaling information associated with the mobileservice data, and known data; a demodulator demodulating the receivedbroadcast signal; a block decoder block-decoding the demodulated mobileservice data of the plurality of output masses based upon the signalinginformation, thereby outputting the mobile service data of one outputmass; and a Reed-Solomon (RS) frame decoder configuring an RS frame withthe block-decoded and outputted mobile service data, and performingerror-correction decoding on the corresponding mobile service data in RSframe units.
 2. The receiving system of claim 1, wherein the blockdecoder comprises: a plurality of input buffers storing the mobileservice data of a corresponding output mass, and repeatedly outputtingthe stored mobile service data in block sizes for turbo-decoding; aplurality of inner decoders matching data of a corresponding output massbeing turbo-decoded and fed-back with data being outputted from arespective input buffer in block sizes for turbo-decoding, therebyperforming trellis decoding; a plurality of symbol deinterleaversblock-deinterleaving, in symbol units, soft-decision values of mobileservice data of a corresponding output mass being trellis-decoded andoutputted; an outer symbol mapper configuring the plurality ofsoft-decision values being deinterleaved and outputted from theplurality of symbol deinterleavers into one soft-decision value; anouter decoder receiving the soft-decision value from the outer symbolmapper and performing symbol decoding; an inner symbol mapper dividingthe soft-decision value being symbol-decoded and outputted from theouter decoder into the plurality of soft-decision values, and convertingthe divided soft-decision values to fit an input format of the innerdecoder corresponding to the respective output mass; a plurality ofsymbol interleavers block-interleaving, in symbol units, thesoft-decision values of the main service data of the correspondingoutput mass being outputted from the inner symbol mapper, therebyoutputting the block-interleaved data to the inner decoder of therespective output mass; and an output buffer storing the mobile servicedata symbol-decoded by the outer decoder, thereby outputting the storedmobile service data.
 3. The receiving system of claim 2, wherein theinner decoder matches the turbo-decoded and fed-back data with the databeing outputted, in block size units, from the respective input bufferto the same position within the corresponding block, thereby performingturbo-decoding.
 4. The receiving system of claim 2, further comprising:a plurality of feedback formatters outputting null data to the innerdecoder instead of the output data of the symbol interleaver, when thedata being outputted from the input buffer to the inner decoder do notcorrespond to the mobile service data.
 5. The receiving system of claim4, wherein, each time the block-sized data for turbo-decoding areturbo-decoded, at the beginning of a first decoding process, thefeedback formatter outputs null data to the inner decoder instead of thedata outputted from the symbol interleaver.
 6. The receiving system ofclaim 1, wherein the mobile service data are encoded at a coding rate of1/N, wherein N is an integer, and wherein the 1/N-rate encoded mobileservice data divided into the plurality of output masses based upon adiversity degree, thereby being received.
 7. The receiving system ofclaim 6, wherein each output mass is configured of (diversitydegree/N)-rate encoded mobile service data, wherein N is an integer. 8.The receiving system of claim 6, wherein the mobile service data of eachoutput mass are scattered to at least one of different frequencies anddifference time sections.
 9. The receiving system of claim 6, whereinthe signaling information includes a diversity-transmitting methoddescribing the diversity degree and how each output mass is scattered.10. The receiving system of claim 1, further comprising: a knownsequence detector detecting known data included in the broadcast signal;and an equalizer channel-equalizing the mobile service data of theplurality of demodulated output masses by using the detected known data.11. A data processing method of a receiving system, comprising:receiving a broadcast signal including mobile service data divided intoa plurality of output masses, signaling information associated with themobile service data, and known data; demodulating the received broadcastsignal; block-decoding the demodulated mobile service data of theplurality of output masses based upon the signaling information, therebyoutputting the mobile service data of one output mass; and configuring aReed-Solomon (RS) frame with the block-decoded and outputted mobileservice data, and performing error-correction decoding on thecorresponding mobile service data in RS frame units.
 12. The method ofclaim 11, wherein the mobile service data are encoded at a coding rateof 1/N, wherein N is an integer, and wherein the 1/N-rate encoded mobileservice data divided into the plurality of output masses based upon adiversity degree, thereby being received.
 13. The method of claim 12,wherein each output mass is configured of (diversity degree/N)-rateencoded mobile service data, wherein N is an integer.
 14. The method ofclaim 12, wherein the mobile service data of each output mass arescattered to at least one of different frequencies and difference timesections.
 15. The method of claim 12, wherein the signaling informationincludes a diversity-transmitting method describing the diversity degreeand how each output mass is scattered.